This paper deals with the fabrication of micro flat drills with a diameter of 5 μm by precision grinding and their application to micro drilling into titanium alloy. Micro flat drills were made of ultra–fine grained cemented carbide which contained WC particles with a diameter of 90 nm. The fabricated drills were used in the drilling with or without ultrasonic vibration. In the drilling test, the effects of the ultrasonic vibration on the drilling accuracy and drill life were investigated.

View full abstract

The machinability in micro drilling depends on the ability of chip removal. This paper deals with cavitation effects in cutting fluid using the ultrasonic vibration in order to activate the chip control. The thrust component is observed when drilling SUS304 by (TiAl)N coated tool of a 0.2mm diameter. In addition, the behavior at cavitation is observed in order to clarify the feature of this method. The application of ultrasonic vibration to cutting fluid restrains an upward tendency of thrust component. The amplitude of cavitation movement depends on the distance between horn and hole.

View full abstract

In this study, we investigate an ultrasonic–vibration–assisted end milling technique for improving the milling accuracy of products using small–diameter and high–aspect–ratio ball–nosed end mills. In our experiments, several mold cavity shapes and fine patterns are machined by the above–mentioned ultrasonic milling technique on copper workpieces used as electrodes for electrical–discharge machining. As a result, we clarify that the improved cutting performance parameters, such as a reduced burr height, a high geometrical precision and a small surface roughness, are obtained by the proposed ultrasonic milling technique.

View full abstract

In the field of cutting with ultrasonic vibration, several studies about formation of chip, measurements of vibration amplitude on cutting tool, and so on, have been reported. However, there is no report that observation of cutting region during cutting with ultrasonic vibration, since ultrasonic vibration is too fast to observe by microscope. In this study, the technique to picture in band of ultrasonic are suggested and picturing system that synchronizes with the ultrasonic vibration is developed. Cutting tests are performed with 60kHz ultrasonic vibration cutting system, and results of picturing of aluminum and die steel during cutting tests are shown and it is shown that the picturing in the optional phase in ultrasonic vibration is possible.

View full abstract

Material removal mechanism of grinding is explained by the theory of successive cutting edge spacing. An Engineered Tool has been developed to perform high–quality ductile mode grinding of brittle materials. The tool has multi–cutting edges that are uniform size, form, and spaces. This paper discusses an experiment to explore adequate successive cutting edge spacing. Single point diamond tool was attached on precision turning machine to cut single crystal Si wafer with vibration excitation. As a result, the phase shifts of machined traces were ascertained corresponding to the calculation of cutting edge′s motion.

View full abstract

The surface finishing is a very important process to produce a die. Because the die surface form is transferred to the final plastic products. At present, the surface finishing of the die is carried out by manual operation of skilled worker. However, there are some obstacles to get high efficiency and surface uniformity. In order to solve the subjects, in this study, ultrasonic machining (USM) is selected. Alumina fiber grinding stone (#1000,φ2.0mm) is vibrated about 28kHz, and the amplitude is about 5.1μm at no–load. To find optimum machining condition (with ultrasonic, without ultrasonic, contact pressure, etc.), various experiments were carried out and the surface roughness was measured on NAK80 die steel. By the USM, the surface roughness Rz was improved from 1.89μm to 0.27μm in this study. Therefore, the effect of ultrasonic was confirmed.

View full abstract

″Non abrasive ultrasonic vibration polishing″ as a new method of polishing CVD diamond films had been proposed and it was clarified that the titanium is the best tool material for polishing and thin oil film applied on working surface accelerates polishing speed by preventing adhesion of titanium to diamond. Therefore in order to apply this method to practical use, surface polishing was attempted. As a result, it is obtained that smooth surface is realized by crossing the first tool feed direction and the second direction, and Smoother surface is realized by moving tool in the same direction than the vertical direction to the vibration direction.

View full abstract

A polishing system assisted by the ultrasonic vibration has been studied. A felt buff is attached on the polishing tool top and loose abrasives in slurry are supplied there. The polishing tool can be rotated independent with the ultrasonic movement. A polishing state in the tool top is observed, and the polishing mechanism is examined. It reports on the effect of polishing.

View full abstract

[in Japanese]

View full abstract

Ion beam fabrication (IBF) is suitable for figuring high precision optics elements used for reflective optics of extreme ultraviolet lithography (EUVL). A dwell time control of an ion beam is performed in shape correction of the optics elements. For this purpose, it is necessary to stabilize an ion beam in time and space. At first we investigated time stability of Ar ion beam and also the current density distribution of the beam. Next we examined the current density distribution of the ion beam when the beam was squeezed with aperture. As a result, it is found that the ion beam current was unstable for five hours after ignition of plasma, then it become stable for five hours. Also, the distribution of the current density might change depending on the distance from aperture when the beam was passed through it.

View full abstract

Ion beam figuring (IBF) is suitable for figuring high precision optics elements used for reflective optics of extreme ultraviolet lithography (EUVL). A dwell time control of the ion beam is performed in shape correction of the optics elements. For this purpose, it is necessary to understand the relation between the beam profile and the processed profile. Then, the removal rate, the processed profile and the space divergence of the ion beam when the ion beam was squeezed to several–mm using a round aperture was investigated. Next, the relation between the current density distribution and the processed profile using the aperture was investigated. As a result, the processed profile changed by the distance between the sample and the aperture. Moreover, it has been understood that the processed profile was corresponding to the current density distribution.

View full abstract

We investigated the smoothing effect of ion beam etching on metal surfaces smoothly cut by a single–crystal diamond tool. Copper surfaces were turned to form optical surfaces with a smoothness of nm order. Then, the surfaces were applied with resist, and processed using ion beams with an optimum incidence angle. After the ion beam process, the copper surfaces were evaluated with an atomic force microscope or an optical surface profiler. Moreover, we calculated the power spectrum density distribution for spatial frequencies of the processed surfaces. As a result, the surfaces cut to a smoothness of nm order were further improved by the ion beam process. The tool marks on the initial surfaces were removed by the ion beam processes.

View full abstract

[in Japanese]

View full abstract

For the purpose of machining ultra high frequency quartz resonator, we study making of quartz wafer with uniform thickness by numerically controlled plasma CVM. In this paper, correction of thickness distribution of quartz wafer by numerically controlled plasma CVM was carried out. And spurious mode in the resonance curve was reduced by improving the parallelism of the quartz wafer.

View full abstract

[in Japanese]

View full abstract

Extreme ultraviolet lithography(EUVL) is developed as a next generation′s semiconductor device fabrication technology. In the EUVL system, the reflective optics is used, and flatness of 50 nmp–v or less is demanded to the mask substrate. This performance cannot be achieved by conventional mechanical machining method. For this request, we are proposing to apply the numerically controlled plasma CVM as a fabrication method for mask substrate. In this paper, we report the machining characteristic of quartz glass that is one of the mask substrate materials.

View full abstract

The machining method which has high spatial resolution and mass productivity at the same time is required in the field of semiconductor manufacturing but also the field of biotechnology etc. To satisfy this request, we developed the new machining method utilizing atmospheric pressure plasma. In this method, fluorine radicals generated in the plasma are blown off to the workpiece surface from small size orifice which has diameter of 10 – 20μm. We achieved that 130μm as a spatial resolution, and also achieved 0.01mm³/h as an etching rate.

View full abstract

Emission spectrum of visible light emitted from an atmospheric chemical vaporization machining (CVM) plasma is recorded with a grating double monochromator coupled with a cooled CCD camera. The plasma gas temperature is estimated by comparing the observed rotational spectra of several diatomic molecules with a spectral simulation program based on Frank–Condon principle. An asymmetricity of sheath electric field strengths, which caused by material differences, is observed as the quadratic Stark effect of severak neutral lines for helium. The field strength is estimated by comparing the Stark shift patterns to numerical simulation based on a quantum perturbation theory.

View full abstract

Si(001) surfaces processed by EEM are clarified to be very flat ones with a flatness of 0.1 nm (RMS). In this study, we investigated the reason why such flat surfaces could be reailzed. In particurar, we focused on affect of ultra pure water and dissolved oxygen in EEM fluid water on processed surfaces. Flatness of Si(001) surfaces became worse, being dipped in ultrapure water. On contrast, they were kept for more than 2 days, being dipped in EEM fluid water. There were no difference of surfaces roughness and removal rate between presence and absence of dissolved oxigen in EEM fluid water.

View full abstract

The purpose of this development is to polish titanium materials to mirror surface by electropolishing method. The method which had two processes was reported by the previous report. One is the electrolytic process by the combination of high and low voltage. The other is the oxide film removal process under the condition that electrolysis is stopped. However, the electrolyte used in previous method has flammability and contains deleterious substance. This time, high quality electropolishing of titanium was effected by using the safety electrolyte produced from ethylene glycol and sodium chloride(NaCl).

View full abstract

This paper describes the elucidation about influence of dilute NaCl electrolyzed water on surface character of nickel material. First, the immersing experiment was conducted which is immerse industrial pure nickel material of 99.3mass%Ni and plating side of nickel into the electrolyzed reduced water and electrolyzed oxidized water of dilute NaCl. Next, weight, externals, and the surface shape of the samples to which immersing experiment was done were confirmed. Furthermore, the surface of the samples of 99.3mass%Ni industrial pure nickel material that after immersing was done was analyzed by Auger electron spectroscopy, and the change in the chemical composition and the change of the oxide film thickness etc. were clarified.

View full abstract

Electrochemical etching in ultrapure water is a precision and clean processing method using chemical reaction of OH^– ions with atoms on the surface of the workpiece without deteriorating the physical properties of the workpiece. In this study, to achieve high–speed and highly accurate processing, we developed a water splitting electrode. Electrolysis of ultrapure water and electrochemical etching in ultrapure water was carried out using this electrode. As a result, the electrolysis current and the etch rate increased when the water splitting electrode was used compared with when unmodified electrode was used.

View full abstract

As a new ultra–precision and ultra–clean processing method, we developed a machining method in ultrapure water. In this method, OH radicals produced from OH– ions in ultrapure water are predicted to take a major role. So we measured OH radicals produced at anode electrode surface using a reagent that reacts selectively with OH radicals. And it was found that OH radicals were produced at the anode electrode in the course of electrolysis of ultrapure water. By simple arithmetic, 0.35% of OH radicals produced were detected but major parts were supposed to be used to produce oxygen.

View full abstract

We proposed a new cleaning method for silicon wafer using high–speed shear flow of ultrapure water along the surface in order to develop an eco–friendly and low–cost cleaning method without using any chemical solutions, and cleaning experiments for the compulsorily polluted silicon wafer with copper were conducted.
As a result, under the experimental conditions of 50m/s average flow velocity and 400 sec cleaning time, the density of copper atom on the silicon surface decreased from 5×10¹³atoms/cm² to the level of 10⁹atoms/cm² which exceeds the performance of ordinary cleaning methods using chemical solutions.

View full abstract

[in Japanese]

View full abstract

It is a proposition for manufacturing to shorten the time of the product development, and to send off the product suitable for consumer needs promptly. Then, processing information at the time of cutting RP is acquired, and the development by the delivery of processing information to the real processing is aimed at.The current of the spindle motor was acquired as processing information, and the analysis was tried.

View full abstract

In the mold machining, ball end cutter is usually used. Rather large cutter and very dense cutter path with small cutter feed are needed in using the ball end cutter for accurately finishing the mold surface, but they often cause long machining time and large remained material. In order to solve these problems, a new cutter with composite shape of round end cutter and ball end cutter is developed. In this paper, the authors proposed a cutter path computation method and milling simulation method for machining with this composite shape cutter. In the path generation and milling simulation, swept volume computation when the composite shape cutter moving along the line segment is important. The authors proposed a new algorithm of the swept volume computation. A path generation and simulation program is developed and some computational experiments are performed.

View full abstract

[in Japanese]

View full abstract

A smart engineering system requires that its all components can interact with their environment and adapt to changes in both space and time. From this point of view, assistive device systems (ADSs) differ from the usual robotics systems in that the interaction between users and devices in ADSs is generally much more direct and closer, so that users and devices should be able to mutually adapt to each other. This inspired our approach, which takes advantage of not only devices′ adapting to users but also users′ adapting to devices by trial and error, based on the device–user interaction. Several problems of how to realize such mutually adaptive assistive device systems would be discussed, and some of our ideas and approaches would be introduced. The efficiency of the interaction based learning method was verified by its application to two assistive device control tasks: a myoelectrical hand control for wrist amputees, and an Electromyogram (EMG) automatic Functional Electrical Stimulation (FES) switching for gait restoration for hemiplegics. Results were shown with discussion.

View full abstract

The objective of this paper is to understand human motion, particularly lifting–up motion for controlling a wearable power assist device. Conventional studies on the motion analysis only consider two–dimensional motions assuming symmetrical motion. However, actual human motions are three–dimensional. This paper presents the analysis of three–dimensional position data of human lifting–up motions are acquired by an optical motion capturing system.

View full abstract

Neutral networks, which are landscapes containing neighboring points of equal fitness, have attracted much research interest in recent years.
In this paper, we extend the deletion method for steady–state GA in order to control population diversity.
And three deletion methods are applied to Royal Road Functions, which have some neutral networks in the fitness landscapse, in order to investigate the relation between the GA performance and the population diversity.
The results show that a population conversed in fitness space moves faster than diversed on a neutral nework.

View full abstract

In recent years, handling items, the address for delivery, etc. are diversified in the distribution center. Therefore it is important to form effective dispatch and stowage plan. However, since it is difficult to form an effective plan in fact, a dispatch plan is a deed by rough calculation, and it depends for a stowage plan on experience of the worker of the spot. In this research, the system which draws up the effective dispatch and stowage plan using GA was developed.

View full abstract

This study deals with development of past similar cases reference system based on the Neural network learning and Self–organization Map. The system shows similar cases as a Map constructed by SOM, and weight parameters of features are updated by case selected by an engineer based on Neural network learning algorithm. This paper describes a concept and a summary of a system to develop.

View full abstract

Our researcher′s group had developed a toolkit for developing decentralized systems. The toolkit can easily describe distributed systems by using C language, and has ability of dynamic modification of its configuration. This report describes outline of the toolkit and ways of decentralized system configurations by the toolkit. Finally, a calculation of the cutting tool path and a calculation of inverse–kinematics of multi–jointed robot arm based on decentralized control method are indicated to confirm feasibilities of the toolkit.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

This study describes mechanical properties of polypropylene(PP) and Nylon66 matrix composites with surface treated CNFs(vapor grown carbon nanotubes:VGNFs and vapor grown carbon fibers:VGCFs). Fillers prepared in wet process are aluminate coupling VGNFs(Al–VGNFs),oxidation VGNFs(o–VGNFs), and amino–functionalization VGNFs(a–VGNFs). Fillers prepared in dry process are acetylene–plasma coating VGNFs and VGCFs(C2H2–VGNFs,VGCFs). Raman and FTIR spectra indicate that amino groups formed on the VGNFs in amino–functionalization. And methyl, methylene, and carboxylic groups are contained in the VGCFs by plasma coating. Granular film is observed on the CNFs surface by SEM and TEM. Matrix composites were obtained by twin screw kneader, and specimens were fabricated by injection molding. The tensile strength of PP matrix composites with Al–VGNF and a–VGNF are 10% higher than those of PP with VGNF. The Young′s modulus of Nylon66 matrix composites increased sligtly by all the treatments, but the tensile strength and the fracture strain are improved by only an aluminate coupling agent. Adding C2H2–VGCFs improved Young′s modulus and tensile strength of PP composites despite low coverage and addition volume.

View full abstract

Carbon nanotubes (CNTs) are expected to be a new functional material. We studied Polypropylene (PP) matrix composites filled with vapor grown carbon fibers (VGCFs and VGNFs) for applications of micro–scale products were fabricated by thin–wall injection molding. Young's modulus and tensile strength of the molded specimens were measured and the effects of thickness are discussed. As a result, though Young's modulus and tensile strength of VGCF/PP composite do not increase in the range of 0.1 mm to 0.5mm in thickness in comparison with those of neat PP, VGNF/PP composites increases with decreasing thickness of specimens. Then from SEM observation, it is found that there are high density and highly oriented layer near the surface.

View full abstract

Ultra–high–speed injection molding gradually proved to be quite useful for high transcription rate molding of microscopic grooves. In this study, we attempted to combine this technology with the well–known injection compression molding, which is widely utilized in the molding of CDs and DVDs, for realizing a higher transcription rate as an ultimate transcription molding technology. In this paper, the results obtained using a stamper with line and space patterns of 3 to 5μm in line width (depth and pitch; 5μm) and PMMA were reported and discussed in detail.

View full abstract

An injection mold for the simultaneous transcription molding from two different directions was successively developed. In this mold, the closings of the both sides of L–shaped cavity could be operated independently by introducing a hydraulic cylinder to the second cavity side. Using stamper with prism pattern of 25um–groove pitch, molding experiments were carried out by an ultra–high–speed injection molding machine, and these results proved that transcriptions in the both sides of L–shape were evidently improved by ultra–high–speed injection.

View full abstract

We proposed a x–y movable cavity block in which 21 optical fiber sensors or 4 pressure sensors were installed in order to detect the melt passing timing at each fiber sensor edge or to measure the pressure profiles in previous work. In this study, the cavity flow pattern and the pressure distribution were measured by this mold in the partial thin–wall cavity with thin–wall area of 0.05mm in thickness. By shifting the location of the cavity block step by step in the x and y directions, we could successfully measure the whole cavity filling patterns and cavity pressure distributions in partial thin–wall cavity by overlapping all the detected data in a cavity area under ultra high–speed injection conditions up to 2000mm/s in screw speed.

View full abstract

Using a cavity surface pressure distribution measurement method which can simultaneously measure melt pressure as surface distribution over the whole injection mold cavity, we measured the cavity surface pressure distribution over a cavity for three kinds of resins, namely crystalline polymer low density polyethylene, liquid crystalline polymer, and amorphous polymer general purpose polystyrene. The results confirmed that higher residual pressure is generated for resins which cool and solidify easily.

View full abstract

Using an injection mold produced by a metal laser sintering combined with high–speed milling, cooling channels are arranged at effective positions. It promotes the cooling speed and improves the shape accuracy. In this research, spirallyformed cooling channel was located between the ribs where heat accumulates and causes the temperature difference in the work piece. The effect of the reduction of the warp has been confirmed compared with a steel mold with conventionalcooling channels. Analyzed temperature in the resin and the displacement of the warp agreed well with the experimental result.

View full abstract

Digital collaboration is defined as man and man collaboration through computer network. Production system with human resource is thought as a product system. A product has it′s product life cycle and in each phase of this life cycle there exists some collaborations between man and machine. In the same way, the production system has it′s life cycle and collaboration phases. In this paper, how a digital collaboration system is related to manufacturing system that is a subset of the production system. A platform for digital collaboration is proposed. And some ways of collaboration of this platform are proposed for new manufacturing system life cycle.

View full abstract

In order to realize the link design to manufacturing system seamlessly and the traceable manufacturing system, it is necessary to represent the semantics of information independently of any implementations. Moreover, the quality of data that represent information should be ensured during product life cycle. In this research, the Digital Semantic Model that fulfils the above requirements is proposed. In this paper, Modeling and implementation of Digital Semantic Model for machining is reported.

View full abstract

A Sequence control has been adopted for many years. But, as the circuit design of the sequence control depends on the experience of production engineers, it is insufficient to systematize the circuit design of a sequence control. The paper researches the creation system which automatically generates the perfect network figure. In order to generate the perfect network figure, the paper proposes the methods of generating two databases from time chart. These two databases are called as the operation database and the subordinate database. In order to ascertain the goodness of the developed method, it was applied to the self–maintenance circuit.

View full abstract

In this research, the configuration of an autonomous decentralized manufacturing system using machine tool agents is proposed. The proposed system can accommodate high–mix, very–low–volume production, and provide flexibly to adjust to sudden failures. In this report, the implementation method of the process planning function using the product model and the machine tool model is examined. The machine tool model consists of machine type, machine specification, tool data, and etc. The machine tool model is described by XML. The functions of each machine tool can be derived using the machine tool model. The process plan for each product can be generated based on machine tool functions. A machining schedule can be obtained by using the generated process plan.

View full abstract

In this research, a product agent is proposed for the configuration of an autonomous decentralized manufacturing system which flexibly responds to high–mix, very–low volume production. In this report, the composition method of a product agent is examined by consideration of the process planning function. When a blank workpiece is put on to the production line, the product agent is dynamically generated with product model. According to the state of each machine tool in the factory, the agent plans the machining process by itself. The agent selects one process plan from generated several plans based on total machining time. Trial implementation of a product agent which has a process planning function was done. In this trial, the busyness of a machine tool is considered in the process planning.

View full abstract

There are many de facto standards of information communication systems depending on industries for device level for manufacturing systems. Also information collaboration system between device level and manufacturing execution system level is needed. Therefore, this research discusses an environment of information collaboration between device level and manufacturing execution system level for multi–vendor and multi–device manufacturing systems. This paper describes a method to grasp production progress information which should be provided to the environment at DNC terminal, and a development of prototype system based on the method.

View full abstract

To realize effective product manufacturing, the following key challenges must be met: (1) Optimum design solutions, rather than simply improvements of existing designs, should be searched for, or else survival in competitive environments that require superior product performance and quality along with lower manufacturing costs will be problematic, (2) To establish product manufacturing infrastructure that supports responsible modern living, optimum design solutions must consider a comprehensive range of factors such as product performance and quality, manufacturing cost, safety, environmental and resource impact at all stages, from raw material acquisition to final disposal, ergonomics, the emotional satisfaction of people, and so on, and (3) To generate new products that improve the comfort and quality of our lives, design systems that support these efforts should be constructed. The roles that optimization techniques play, and the fundamental procedures employed to achieve the above challenges are discussed in this article.

View full abstract