In this paper, the temperature distribution of the meshing tooth surface of hypoid gears was obtained using infrared thermography. In addition, to investigate the effect of the offset amount on the vibration characteristics, the vibration during gear driving was measured using an acceleration pickup, and the change in vibration owing to the offset amount and the driving conditions were quantitatively evaluated from the correlation with the thermal image. Furthermore, we attempted to extract the tooth contact area using thermography by quantifying the actual tooth contact area through a tooth contact test using paint and comparing it with the tooth-surface temperature distribution.

Contact between the tool and the workpiece during machining has a significant effect on the vibration characteristics of the machine tools. In this study, contacting rate is defined as the contact time per unit time based on the detected contact between the tool and workpiece during the excitation tests, and relationship between the contacting rate and vibration characteristics is investigated. As a result, it was confirmed that the natural frequency increased significantly when the contacting rate was over 90%, and the vibration damping increased significantly when the contacting rate was in the range of 0-10%.

A comprehensive analysis of the tool wear modes and mechanisms was performed to clarify the influence of the ultra-fine bubble (UFB) inserted coconut oil-based metalworking fluid (COCO) for extended tool life for machining Inconel 718. The wear progression was examined for the interrupted cutting intervals while using UFB inserted COCO and the tool performance was evaluated according to the ISO 3685;1993 standard. Usage of the UFB inserted COCO has demonstrated 30% extended tool life and lower adhesion compared to the commercially available synthetic oil-based metalworking fluid (MWF (SynO)). The clarifications relevant to the performance and the increment of the tool life on machining of Inconel 718 while using the UFB assorted green MWF added significant industrial value to the sustainable machining context of difficult-to-cut materials.

When processing small parts, which have been rapidly developing in recent years, it is necessary to consider the best processing method for the part size. Laser-based processing methods have attracted attention in such a production system. In this paper, the theory of laser quenching and forming is explained, and the problems encountered during processing are discussed. In addition, origami engineering is considered as a concrete example of an application, and the performance of a prototype of a plate spring is examined. The performance of the spring was simulated using the finite element method, and from the results, problems in creating three-dimensional shapes were extracted.

Although planetary gear mechanisms are used in many machines, their dynamic characteristics have not been fully elucidated because they have multiple input-output relationships and planetary motions with different meshing states. Therefore, we attempted to model the planetary gear mechanism to clarify the influence of internal phenomena on external phenomena. In this study, to dynamically model the planetary gear mechanism, we proposed a method to draw a block diagram from the equations of motion of each element and simulate the response characteristics of the planetary gear mechanism. The validity of the simulation method was compared with that of the resonance frequency.

In smart manufacturing, human-cyber-physical systems host digital twins and IoT-based networks. The networks weave manufacturing enablers such as machine tools, robots, CAD/CAM systems, process planning systems, enterprise resource planning systems, and human resources. The twins work as the brains of the enablers, that is, the twins supply the required knowledge and help enablers solve problems autonomously in real-time. Since surface roughness is a major concern of all manufacturing processes, twins dedicated to solving surface roughness-relevant problems are needed. The twins must machine-learn the required knowledge from the relevant datasets available in big data. Therefore, preparing surface roughness-relevant datasets to be included in the human-cyber-physical-system-friendly big data is a critical issue. Preparing such datasets is a challenge due to the lack of a steadfast procedure. This study sheds some light on this issue. A state-of-the-art method is proposed to prepare the said datasets for surface roughness, wherein each dataset consists of four segments: semantic annotation, roughness model, simulation algorithm, and simulation system. These segments provide input information for the input, modeling, simulation, and validation modules of digital twins. The semantic annotation segment boils down to a concept map. A human- and machine-readable concept map is thus developed where the information of other segments (roughness model, simulation algorithm, and simulation system) is integrated. The delay map of surface roughness profile heights plays a pivotal role in the proposed dataset preparation method. The successful preparation of datasets of surface roughness underlying milling, turning, grinding, electric discharge machining, and polishing shows the efficacy of the proposed method. The method will be extended to the manufacturing processes in the next phase of this study.

In smart manufacturing, manufacturing enablers (machine tools, robots, CAD/CAM systems, monitoring systems, and alike) and human resources need knowledge for performing high-level cognitive tasks such as monitoring, understanding, predicting, decision-making, and adapting. The ever-growing knowledge-bases in the human-cyber-physical systems supply the required knowledge. The knowledge in the knowledge-bases must be human/machine-comprehensible, represented by a scalable ontology-based representation method. In reality, representation methods are mostly domain-specific and follow strict ontological formalism. This study addresses this issue by presenting a semantic annotation-based representation method. The annotation mechanism follows knowledge-type-aware concept mapping. A Java^™-based computerized system, denoted as Semantically Annotated Data Visualization System (SAD-VS), is also developed for human/machine comprehensibility of the represented knowledge. The proposed annotation mechanism and SAD-VS are demonstrated in detail, considering a real-life manufacturing experiment. The findings of this study can increase the usages of experimental datasets more effectively while developing digital twins.

The demand for carbon fiber reinforced plastic (CFRP) has been increasing in various fields. Therefore, there is a need for high-quality and high-efficiency processing of this material, which requires trimming and drilling of excess CFRP after molding. In this study, a cubic boron nitride electroplated ball nose-endmill was developed. This novel tool can be switched between cutting and grinding modes, thus eliminating the need for tool change. In this paper, the phenomenon of delamination at the hole exit is discussed based on the relationship between the change in axial feed rate (a parameter of helical motion) and cutting force.

There have thus far been no reports on the drilling of microholes in cemented tungsten carbide by cutting. Such drilling was therefore attempted using micro-diamond end-mill-type tools fabricated by EDM. The assistance of ultrasonic oscillation was employed to reduce cutting force and thus to prevent tool breakage. At an ultrasonic oscillation half amplitude of 0.2 μm, the drilling of microholes up to 15 μm in depth was possible at a feed speed of 0.05 μm/s using a 20-μm-diameter tool.

In this paper, we apply micro-Raman tomographic imaging (mRTI) method on surfaces of the engineering ceramics with abrasive wear for evaluating the surface quality, aiming to the applications in failure analysis of the ceramic components, development of the abrasive machining and inspection techniques of the ceramics products. Observations of subsurface damage were successfully conducted on single crystal materials such as sapphire (single crystal of α-Al₂O₃) using mRTI due to the transparency of the material. We attempt to measure the surface of alumina ceramic plates using mRTI. Since light diffusion due to grains of the polycrystal substance and surface roughness disturbs the measurement, we utilized the surface smoothing and oil immersion measurement to reduce scattering. On the measurements of abrasive polished surface, extracted peak feature values of typical Raman peak at 417 cm^-1 such as the peak shift, peak width and peak intensity are imaged as the distribution of the damage by abrasive wear like tomographic measurement. The wear damages expanding to more than 10 micron-depth beneath the surface are visually recognizable in the image.

In this paper, we introduce an intelligent diagnosis technique for micro-hole drilling state based on the analysis of acoustic emission (AE) signals emitted during the process. Through the analysis of the AE signal waveforms in both the time and frequency domains, we attempted to estimate tool condition in micro-hole drilling, and tried to diagnose abnormal state that may lead to tool breakage.

The stable production method of nanofiber non-woven fabrics by the improved melt blow method and flash spinning method in consideration of mass productivity was investigated in a previous study. This report focused on filter characteristics as one of its applications; both a uniform distribution model and a fiber diameter distribution model have been proposed. First, the filtration performance of the fiber was experimentally tested by varying parameters such as the fiber thickness, filling rate, and fiber diameter. Second, the pressure loss and flow resistance were simulated using computational fluid dynamics (CFD) flow-analyzing software. It was confirmed that the proposed fiber diameter distribution model was closer to the experimental value than the uniform distribution model, and the relations among filling rate, fiber diameter, and flow resistivity were also verified.

There is a fused deposition modeling method as a three-dimensional modeling method that mainly uses a resin filament. By this method, modeling using a resin filament containing a metal is also possible. When the metal-containing PLA filament was three-dimensionally modelled under the same conditions as the pure PLA filament, defects were likely to occur in the modelled object regardless of the printing speed, melting temperature, and bed temperature, resulting in inferior strength. In addition, when a JIS standard antibacterial property test was conducted on a PLA filament model containing copper even at a few percent, antibacterial properties were confirmed against multiple bacteria.

High Speed Precision Dry Hobbing, in which cutting speed is from 1000 to 2450 m/min with axial feed 0.3mm/part-rev., achieved gear accuracy equivalent to a shaving process; ISO grade 6 in profile, ISO grade 3 in helix, and surface roughness Ra 0.3 by a single-cut strategy. The stable cutting force and low workpiece temperature by the cutting speed of 2450 m/min were observed in spite of producing red heated cutting chips. By replacing conventional hobbing and shaving with high speed precision dry hobbing, an environmentally friendly manufacturing process can be achieved.

The surface properties and microstructure of metallic materials can be enhanced by various methods. In particular, a shot peening treatment is commonly used to increase the surface residual stress and fatigue life. When a heated work material is shot-peened, the components of the shot grid diffuse to the processed material surface and partially alloy with its elements. As a result, the residual stress and lifetime of the alloyed phase increase. The proposed hot shot peening method can effectively suppress the formation of surface cracks without increasing manufacturing costs.

The high cutting load in gear power skiving is a severe problem. In this research, the cutting force is reduced by employing different radial infeed strategies while maintaining the cutting efficiency. Setover is applied to realize an additional motion of the cutter for varying local cutting conditions. The numerical analysis on uncut chip geometry was carried out to investigate influences of setover, followed by the experimental verification. As a result, setover imposed great influences on the cutting process including the cutting chip, cutting force, etc. In the cutting force measurement experiment, the proposed feed strategy achieved a force reduction up to 49% in most compared with the conventional radial infeed strategy.

Burnishing, a type of surface modification process, is an effective processing method because it can improve surface roughness, fatigue strength, and corrosion resistance in one process, and it can be performed on CNC machine tools. On the other hand, processing of thin-walled materials and free-form surfaces is not widely used because such material can be easily deformed due to the large burnishing force. This research aims to develop a novel burnishing tool that can process thin-walled materials. The prototype of the burnishing tool that cancels deformation by applying force from both sides was designed and fabricated. According to the experimental results, the surface roughness was improved to about Ra = 0.5 μm, and the deformation was reduced to about one-fourth of the conventional burnishing method.

The influence of changes in the physical properties of lubricants on thermal elastohydrodynamic lubrication solutions is examined numerically at the nominal line contact for both Newtonian and non-Newtonian fluids. Specific heat, thermal conductivity, density, and viscosity were considered as functions of temperature and pressure for polyalphaolefin, polyglycol, and mineral oils. It was found that, when considering the physical and rheological properties of lubricants individually, the solutions were over- or under-estimated. The thermal conductivity formula mostly corresponds to solutions for both fluids. The effects of changes in the physical properties of non-Newtonian lubricants were shown to be less than those of Newtonian lubricants. Near-identical qualitative behaviors occurred regardless of oil type under these lubricant models.

As machine tools are required to have higher performance and more functionalities, the importance of sheet metal parts has been increasing. However, the design, functionality, and manufacturing technology of sheet metal parts of machine tools have almost never been systematically studied. Therefore. this study investigates a new production system. First, characteristics of sheet metal parts are analyzed, a fiber laser welding robot is installed to competitively manufacture sheet metal parts without relying on tacit knowledge of skilled operators, and finally, a hablanian plot is used to identify optimum welding conditions.

A new jig design for taking an MRI of an experimental mouse’s lumbar spine, which is called “positioner”, is proposed and manufactured in this paper. Generally, the MRI is not suite for various movements during imaging. Hence, the positioner must fix an anesthetized mouse with consideration of the mouse shape with keeping alive and reduce some disturbances of the taken images. Some detailed specifications for the positioner is revealed in advance. Based on the revealed specifications, the positioner is designed by a 3D-CAD (Computer Aided Design) system. The positioner is also manufactured by a 3D printer with using ABS (Acrylonitrile butadiene styrene) . The MRI test is carried out by using the proposed positioner and some clear lumber spine images can be obtained. A feasibility of the new designed positioner is demonstrated through a case study.

A concept of digital twin for machine tools digital twin for cutting simulation is proposed. The suggested digital twin is a time-domain simulator for processes of machine tool consisting of a controller model, a machining process model, and a machine dynamic model. In this report, an online system identification method to model machine dynamic is developed. An ARX vibration model is adopted as vibration model. Time domain simulations of TCP vibrations are calculated with the identified vibration model. The results of the time-domain simulation showed a better accuracy than typical system identification methods in frequency-domain.

Compliant mechanisms, which realize a functional mechanism by designed deformations where that material deform elastically, is expected to reduce number of mechanical parts or assembly costs. Fiber reinforced polymers – additive manufacturing (FRP-AM) can expand the compliant mechanism functions. The purpose of this study is to propose the structure optimization method for compliant mechanisms considering its continuous fiber path in FRP-AM. In the proposed optimization method, a compliant mechanism structure is represented as a geometric graph and the optimum structure is searched with genetic programming, which is one of the metaheuristic methods. A case study is conducted using a gripper with compliant mechanism.

Thermally excited evanescent waves generated due to local phenomena of materials is served as a local probe of temperature. The nanoscale near-field spectroscopic information of the thermally excited evanescent waves is applicable to nano-thermography or nano-chemical microscopy. In this study, we demonstrated passive-type scanning near-field optical spectroscopy (SNOS) which detects spectroscopic information of the thermally excited evanescent waves without using any external illuminations. The passive SNOS has been developed with grating-based spectroscopic optics which has over 60 % signal efficiencies. Using the developed passive SNOS, we have achieved detecting the near-field signal on SiC at several different wavelengths in the long-wavelength infrared (LWIR) range.

The requirement for Mass production of Microlens array (MLA) mold is increasing. MLA molds are manufactured by 5-axis ultra-precision machining center using an ultra-small diameter end mill. Since visual examination is not good at judging quality of product while machining, the development of effective process monitoring technology is required. The ultra-precision machining center used in this study employs a linear motor and has low sliding resistance while machining. Therefore, machining information is directly reflected in servo information. Focusing on this point, we developed a machine learning-based shape error estimation model using servomotor current alone and discussed its usefulness.

More efficient internal combustion engines have been required for global warming countermeasures. In order to overcome the problem, one of the most efficient method is to realize a non-axisymmetric non-circular inner cylinder machining within several tens of micrometres. However, there is no machine tool coping with the machining method. Our research purpose is to develop the high-performance spindle that can machine parts with non-circle machining such as the inner cylinder profile for EV motors and internal combustion engines with high precision. Based onthe model base simulation, the performance of the positioning control was evaluated by applying a disturbance assuming the cutting force actually applied. Finally, we evaluated the performance of the disturbance observer using the actual spindle.

In micro-joining of glass by using an ultra-short pulsed laser, high intensity of laser beam focusing into a micro-spot inside the glass initiates the nonlinear absorption phenomenon, and micro-area inside the glass can be melted locally. However, it is difficult to achieve high joining strength, since molten area is formed by periodic movement of laser energy absorption point in an optical axis. In this study, the improvement method to control molten area formation by using a spatial light modulator (SLM) was discussed in micro-welding of borosilicate glass by a picosecond pulsed laser. SLM can modulate a wavefront shape of laser beam into the desired pattern image, and it can form different molten area shapes from traditional method.

The Combined process of 3D printing and joining for manufacturing multi-material parts made of plastic and metal was developed. In this process, the lower plastic part having a projection is printed, the metal part having a hole sets on the plastic part and then the upper plastic part is deposited on the metal part, while caulking is formed by 3D printer. The effect of the height and clearance of caulking on the joint strength was evaluated by the tensile shear and three-point bending tests. It was found that squashing of the projection of lower plastic part by the upper part was important to obtain sufficient strength. Although the large clearance is facilitate locating of the metal part, the strength is decreased with increasing the clearance.

Painting work using spray gun requires a steady paint thickness and certain skill. Several studies using robots that teach paths have attracted attention. However, it is complicated to generate a path with a constant paint thickness based on the actual painting parameter because the paint thickness is not displayed by conventional path generation software. This study will include two main steps, initially development of high-functional simulator and afterward automation of painting path generation to complex shape. The purpose of this report is to provide a new coating simulator model that can reflect coating conditions without using a particle level model.

The purpose of this study is to propose a practical tool condition monitoring method in end milling operation. In the proposed method, real-time cutting force simulation is performed in parallel with actual milling operation. The tool condition is recognized by comparing the spindle motor torque, which can be monitored through CNC without additional sensors, with the predicted cutting torque. This method is practical because the parameter required for real-time cutting force simulation can be immediately and automatically identified at the beginning of the milling operation, and it requires no additional sensor installation. The effectiveness of this method was confirmed by the experimental verifications.

T Carbon Fiber Reinforced Plastics (CFRP), which are classified as functional resin, has risen and is replacing conventional materials because of their excellent properties. They have been mainly used for producing the body part of airplanes or cars, as well as the demand for micro machined products manufactured with a lathe used in the medical field are also rising. However, the problems of machining CFRP are, occurrence of burrs and deterioration of finished dimensions due to the significant tool wear caused by the carbon fiber. In order to turn CFRP and maintain a high dimensional accuracy, tool wear caused by the carbon fiber must be reduced. In the study, possibility of combining conventional turning and electric current or electrical discharge machining is demonstrated.

In recent years, adhesive water repellency surface, like a rose petal, is gathering attentions, because this surface is useful for water transport and water gathering from the atmosphere. We found that simple fabrication process of adhesive water repellency surface using moth-eye structure films and scratching. First, nano-scale needle like moth-eye structure films were fabricated by nanoimprint technique. After that, scratch was carried out to these films. As a result, 30 times scratched film has adhesive water repellency, like a rose petal. This film also has low reflectance and high transparency, like a moth-eye structure.

Thermo-elasto-plastic deformation models cannot predict the final shape in multi-stage laser forming. This is because that laser irradiation varies material properties, posture, and stiffness of metal plates during the process. Regarding this problem, authors develop a laser forming simulator, which employs the artificial neural network to correlate the process parameters and the metal plate deformation. In this study, prediction of the deformation demonstrates the feasibility of proposed method in multi-stage laser bending experiments with stainless-steel strips. The influences of network structure on machine learning are investigated, and the influences of conditions are discussed in aspect of prediction accuracy.

This present study is intended to show some test results of fabrication of micro-oscillators by transfer-printing (TP) of Au thin film and inkjet printing of graphene oxide (GO) nanoparticles. Au thin film is formed into a double-supported micro-beam to function as a micro-oscillator on a polymer substrate. Au thin film is also fabricated on a pre-coated Au substrate by atomic diffusion bonding assisted transfer-printing. This micro-oscillator can be driven by electrostatic force with 90 – 210 V of applied voltage and less than 10 kHz. The resonance frequency is 0.28 kHz. GO nanoparticles are deposited on the transfer-printed Au thin film by inkjet printing. The laminated thin film of Au and GO nanoparticles has higher modulus than that of Au thin film.

In this study, Electro-Adhesive Gel Sheet (EAGS) was attached to a robot hand and used as a gripper. Electro-Adhesive Gel (EAG) is a functional elastomer which can change surface adhesiveness depending on an electric field. EAGS is a sheet of EAG fabricated on a flexible electrode substrate. It is confirmed that the electrical current flow inside EAGS is changed when the robot hand with EAGS (EA hand) touches a grounded metal object or slips on it. By applying these current characteristics, the applicability of contact detection and slip detection is investigated to monitor gripping status in robot hand. From the results, EA hand can detect not only the contact but also lifting the object from the base plate. Furthermore, slipping can be suppressed by adjusting an applied potential difference of the electrodes according to the slip detection.

A new processing method is needed for achieving high accuracy and high efficiency in titanium alloy machining. It has been reported that driven rotary machining of hardened steel improves the machined surface and processing efficiency. These results suggest that it is possible to realize high-efficiency machining by employing hale machining with a rotary tool. In this study, hale machining was performed using a driven rotary tool, and the effects of different cutting conditions and cutting environments on the machining characteristics were investigated. The results showed that the tool life was longest at a feed rate of 9000 mm/min because the formation and dropping of adherents decreased as the friction distance of the cutting edge decreased. Furthermore, it was clarified that adhesion formation at the cutting edge was suppressed by lubrication with an oil mist in a minimum quantity lubrication environment. This lubrication effect reduces tool damage and adherence at the cutting edge, and makes it possible to significantly extend the tool life and improve the machined surface quality compared to the results in a Wet environment.

A digital twin that realizes the machining motion function, including the error of the multi-axis machine tool in cyberspace, was proposed in the previous paper. Using actual machining case data and virtual machining case data using digital twins, effective process planning of individual multi-axis machine tools becomes possible. In this paper, a realization of the twinning function of the digital twin by autonomous feedback of actual machining shape measurement is proposed. The digital twin has the same machining capabilities as a real machine tool with kinematic errors to generate the required machining case data using the proposed method.

This research aims to establish fabrication method of hierarchical-period gratings, which are nano-and micro-surface structures composed of several different periods. In this report, we discuss how to control the phase shifts between each period in the fabrication process. A previous research had proposed the controlling method of the phase shifts using a reference grating. We applied this method to fabrication of dual-period grating with an arbitrary phase shift and conducted fabrication experiments of dual-period gratings using Lloyd’s mirror setup controlling the phase shift to be π or π/2 [rad]. At the result, it was verified that the phase shift was successfully controlled.

The final goal of this study is to develop a vision-based method for measuring machine 3D-dynamic motion errors. In this report, a measurement method is proposed, and its resolution and measurement error in plane motion measurement are discussed. The influence of the defocus condition on the detection resolution is analyzed. The displacement of the marker installed on the spindle of the machine tool is obtained through the video captured by the high-speed camera. In order to obtain the displacement of the marker, the center position of the marker is identified by fitting a mathematical function to obtain the position of the intensity peak of the marker. The measurement resolution and accuracy of the proposed method are investigated by experiments. In addition to the model fitting method, edge detection method and threshold detection method are also used for marker position detection for comparison. The model fitting method reach the accuracy of 40 μm and resolution of 7 μm compared with the grid encoder as the reference. The standard deviation of the detected static position is less than 7 μm when the defocus length is less than 190 mm.

Laser metal wire deposition (LMwD) has become an alternative AM method for Ti6Al4V alloy forming while some difficulties still exist, which could be classified as parts distortion, oxidation and uncontrollable mechanical properties of as-built samples. In the present work, the printer with a coaxial laser supplied by two laser irradiation heads was carried out to investigate the microstructure mainly of as-built one bead samples. The results showed that: Under the optical microscope and scanning electron microscope (SEM), and the coarse columnar β phase, typically acicular martensite α' phase and some pores were observed clearly. The size of α' decreases from deposition zone (DZ) to fusion zone (FZ). From FZ to heat-affected zone (HAZ), the α' gradually transferred into epitaxial grains and the pores increased. The forming of pores may result from incomplete heat input or inadequate shielding gas input. Besides, the SIMUFACT software was used to simulate the temperature and residual stress distribution of substrate simultaneously. The results showed that the growth direction of β grains is essentially in agreement with the direction of the maximum temperature. The residual stress distribution of substrate after printing was discussed as well.

This study describes a melt pool morphology during a single track formation in the laser powder bed fusion processes by visualizing with a high-speed camera. The influence of laser incident angle on a scattering of spatter particles and a formation of heat-affected zone (HAZ) is investigated. As results, the laser incident angle was one of the principal parameters determining the metal powder behaviour, and affected the melt pool morphology and the spatter particle behaviour. The HAZ was also formed according to the laser incident angle and the spatter particles were related to the keyhole formation inside the melt pool.

Calculating the interaction between a machining tool and a workpiece is very important in evaluating cutting process. The estimation of cutter-workpiece engagement based on three-dimensional (3D) geometric models needs huge amount of discrete data for representing dynamic states of the cutting tool and the workpiece. In the paper, authors propose a Spatio-Temporal description approach to represent dynamic machining process using four-dimensional (4D) geometric models. As the core of the approach, T-map data structure is newly introduced and a calculation of cutter-workpiece engagement using T-map is proposed. To accelerate the calculation with T-map, several parallel processing strategies are compared.

Vertical articulated industrial robots are widely used to automate various operations at manufacturing production sites. Meanwhile, off-line teaching systems are increasingly being employed to develop robot programs. However, depending on workpiece placements, problems such as sudden changes in posture of the robot and encountering singularity points may occur. In this study, we used manipulability, which represents the kinematic operation ability of the robot, as an index for evaluating robot motion, and examined the method for obtaining an optimum workpiece placement within a practical time limit. Additionally, we applied the proposed method to a sealing process and verified its effectiveness thorough simulations.

Precise temperature control is required in various fields including machine tools and semiconductor manufacturing machines. In order to improve the machining accuracy of machine tools, it is necessary to minimize the thermal deformation of machine tools due to its temperature change. For a cooling purpose, forced fluid cooling systems are used to reduce the temperature change of machine tools. In general, the response of conventional chiller systems is slow. Furthermore, the chiller controls the temperature of target component without feedback loop. Accordingly, the temperature control performance is quite limited. In this study, a sophisticated cooling system with feedback of target component temperature based on proposed temperature control system is developed. A performance of the control system is evaluated for a surface temperature of a built-in motor spindle, experimentally.

Turn-milling is a method of machining a workpiece while rotating it using a rotary tool, and has been widely used recently because a multi-tasking machine having both a turning function and a milling function has been developed. In this machining method, a spiral pattern peculiar to the machined surface is generated. In this report, turn mill processing using an NC lathe and an air spindle is applied and the application method of the resulting miniaturized processing pattern is considered.

In fine wire electrical discharge machining (EDM), oil has been recently used as dielectric working fluid instead of conventional deionized water for more precise machining. However, the influence of physical and electrical properties of the working oil on wire EDM characteristics has not been clarified sufficiently. This study investigated the influence of working oil viscosity on wire EDM characteristics. The results showed that removal rate becomes higher and machined surface roughness becomes larger with the increase of working oil viscosity.

In fine wire EDM using a thin wire electrode for relatively thin workpiece, it is important to evaluate spark distribution state accurately, since the distribution state greatly influences the machining performance. However, it is difficult to measure the spark locations on the order of sub-millimeter by conventional methods, such as branched electric current method. In this study, a new method to measure spark locations by direct observation from the side with a high-speed camera was proposed for accurate evaluation of the spark locations distribution. In order to confirm the advantage of the new side observation model, the number of spark observed with this model was compared with that by the conventional back observation model. Then, the influences of machining conditions on the spark locations distribution were investigated and discussed.

Possibility to form compositionally graded layer on the tool steel surface by EDM using Cr and WC-Co electrodes was investigated in this study in order to discuss the applicability of inexpensive carbon tool steel as metal mold material. Experimental results showed that a compositionally graded CrC-WC containing layer can be formed by EDM finishing on the chromium carbide containing layer using WC-Co electrode, and the surface roughness was less than 1 μm, which indicates high applicability of the surface as a final metal mold surface. It was also found that the tungsten in the compositionally graded layer exists in some states such as amorphous and some crystal structures of tungsten carbide. The surface hardness can be further improved by the compositionally graded layer containing tungsten carbide.

In large-area electron beam (EB) irradiation method developed recently, highly efficient surface smoothing of mold steels with planar shape was possible. However, it is difficult to smooth the side surface of hole shape. In this study, smoothing of side surface by guiding the EB to the side surface under control of magnetic field around the workpiece was proposed. As a basic study for smoothing side surface, L-shaped workpiece was used. It was made clear that the whole area of the side surface can be uniformly smoothed by guiding the EB to the side surface under the control of magnetic field around the workpiece.

Recently, environmentally friendly technologies which is electrical vehicle, low fuel consumption vehicle and etc. are necessary to reduce amount of CO2, NOX and PM emission. To realize environmentally friendly society, fundamental techniques to improve machine efficiency are important. The machines have rotation, stroke and other many movement elements which reduces machine efficiency due to friction loss. Technologies to reduce friction force are valid to improve machine efficiency. Surface texturing techniques which fabricates periodical micro concave on the friction surface are valid to reduce friction force. It is considered the textured surface functions similar to scraped surface with many oil holes which often applied to friction surface of machine tool. Many researchers study the surface texturing technique to reduce friction loss such as laser ablation, fast tool servo machining and etc. In previous research, ultrasonic turning techniques were investigated to improve products quality, reduce tool worn out and extend tool life. Finished surface by ultrasonic turning has periodical ditch originated from tool periodical vibration by ultrasonic oscillation. This paper describes surface texturing technique by ultrasonic turning to fabricate periodical texture on various materials. Stainless steel JIS SUS304, titanium alloy Ti-6Al-4V and aluminum alloy JIS A2017 were tested on these experiments. And textured surfaces were evaluated tribological properties.

Titanium aluminide (TiAl) alloys have higher specific strength and are desired for application to jet engine components. For this study, the machinability and effects for microstructure after cutting of cast and wrought TiAl alloy were investigated. Results show that any TiAl alloy can be machined with no cracks. Furthermore, microstructural bending was observed and controlled by the radial depth of cutting and the degree of tool wear. Finally, by adjusting the cutting conditions, the entire surface was cut from the rough forged state to the blade shape without microcracking.