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This study deals with shoulder cutting phenomena in micro-end-milling of hardened die steel. Demand for micro-end-milling for products in the medical, optical, and electronics industry is increasing. However, in machining with a small diameter end mill that has diameter of e.g., 0.5 mm, the rigidity of the tool itself is low; therefore, cutting conditions must be set to low values to achieve stable machining. We revealed that cutting phenomena became unstable because the end cutting edge was damaged early in shoulder cutting. Therefore, we experimentally prepared a left hand helical tool with a right hand cut to perform complete processing by improving the strength of the end cutting edge. Cutting experiments were carried out while measuring cutting force and observing cutting phenomena, end cutting edge, and machined surface via scanning electron microscopy (SEM). We determined the effects of such tools on fundamental phenomena in shoulder cutting with a small diameter end mill. The rake angle of the tool was improved based on experimental analysis of the damage mechanism of the cutting edge in the shoulder cutting. A result of the examination to investigate the influence of the difference in rake angle on chip evacuation showed that the chip discharge direction was affected by the rake angle; when the angle is blunt, the chips were discharged upward, and the chip discharge performance improved.

The demand for micro-end-milling for products in fields such as the medical, optical, and electronics industry is increasing. However, when machining with a small diameter end-mill (micro-end-mill) with diameters such as 0.5 mm, the rigidity of the tool itself is low; hence, the cutting conditions must be set to low values to achieve stable machining. Therefore, we examined various cutting phenomena that occur during actual machining processes to achieve high machining accuracy, high finished-surface quality, and long tool life. Some studies on micromachining achieved high accuracy, high-grade machining by considering the cutting phenomena. In previous papers, we dealt with the side-cutting phenomena in micro-end-milling of hardened die steels using a high-speed air-turbine spindle with rolling bearing. Cutting experiments were carried out by measuring the cutting force and flank wear of a cutting tool to investigate the difference in cutting phenomena caused by cutting direction in high-speed micro-end-milling. Observation of the machined surface and measurement of the profile of the cutting edge and machined surface were demonstrated. It was revealed that machining quality in high-speed up-cut milling was better than that in down-cut milling. Shoulder cutting, in which both peripheral and bottom cutting edges act simultaneously on the workpiece, was also investigated. A novel small diameter end-mill with left-hand helical tool with right-hand cut was developed to avoid damaging the cutting edge in the initial cutting stage. In the present study, high-quality shoulder cutting of a vertical wall using the new tool was proposed and demonstrated.

Bamboo grows naturally in Japan as an underutilized forest resource, and its fibers have high specific strength and stiffness, so much so that they are called natural glass fibers. In this study, a method for manufacturing a self-adhesive compact material by pressurizing and heating 100% bamboo fiber after extraction using a machining center, without losing the composition of bamboo, is proposed. This molded body is made of a 100% natural material and has a low environmental impact even when landfilled, contributing to the growth of bamboo for use as a raw material. In this study, the formation conditions for maximizing the tensile properties when forming platelets were investigated. First, an analysis of the variance was conducted using the orthogonal array test design to identify the factors affecting the objective variable and determine the contribution of each factor. In addition, estimates of the objective variable for the molding conditions were obtained from the Gaussian process regression model in a Bayesian optimization. Furthermore, as a result of comparing the maximum values of the properties of the molding conditions between the analysis of variance and the Gaussian process regression model, the values of the tensile properties were improved in the Gaussian process regression model.

The importance of micromachining using small diameter end mills and the dies used for them has been increasing in the machining of small parts. However, the reality is that there are various requirements to improve the machining surface, machining accuracy, machining efficiency, and tool life. Therefore, this paper discusses the possibility of satisfying these requirements by high-speed up cut milling in side cutting. The goal of this study was to solve the aforementioned problems, by conducting a detailed analysis of the machining phenomena in order to understand their mechanisms. In particular, the effects of high-speed cutting using a high-speed air-turbine spindle with highly stiff rolling bearings were analyzed. Moreover, cutting experiments were conducted by measuring the cutting force and flank wear of the tool, to reveal the differences in the cutting phenomena relative to the cutting direction in high-speed micro end milling. Description of the machined surface and the measurement of its profile were also included in the discussions. On the basis of the results, high-speed up cut milling is a better choice than down cut milling, furthermore, a high-feed rate further increases machining efficiency and improves tool life.

A furnace is used in the conventional quenching of small work pieces. When quenching is performed using a furnace, the electricity consumption is high because the heating is performed over a long time period. Moreover, the working environment is unsatisfactory because quenching oils and salt baths are used in the process. Laser quenching has attracted considerable attention as a method for addressing these issues. In previous studies of this method, a laser was used to perform whole quenching on a sheet. However, problems such as deformation and tempering can arise during whole quenching on a thin plate. Furthermore, it is difficult to determine appropriate feed speeds and scanning orders. Therefore, in this paper, we propose a quenching method that uses a semiconductor laser to reduce these thin plate quenching problems. Additionally, an evaluation function is provided for quantitatively assessing the feed speeds. We strive to determine the appropriate laser scanning order from an understanding of decreases in hardness and transformation. We then used the evaluation function to appropriately set the feed speed for the whole quenching of a thin plate using a laser. As a result, we were ultimately able to select a suitable feed speed at which whole quenching can be performed.

Currently, carbon fiber reinforced plastics (CFRP) are being increasingly adopted in various fields. Thus, machining CFRP with high accuracy and high efficiency is required. In addition, machining stack materials composed of CFRP and titanium alloys is required. Therefore, in this study, a novel end-mill electroplated with a cubic boron nitride (cBN) abrasive, which has high thermal resistance, is proposed. In order to evaluate the influence of the base metal shape of the proposed end-mill on the machining process, several cBN-electroplated end-mills with different rake angles or chamfers were fabricated and used to cut CFRP. In addition, in order to evaluate the abrasive shape, a blocky abrasive was also electroplated on the end-mill. The results indicate that the negative rake angle is useful to restrain the progression of tool wear. However, in order to obtain the element of cutting and grinding, it is required that the rake angle should be positive. Moreover, the reasonable width of chamfer is effective for restraining the increase in CFRP temperature. Further, a sharp shaped abrasive can more effectively generate a CFRP with a sharp edge compared with a blocky shape abrasive.

In recent years, the performance and miniaturization of portable information devices have rapidly advanced. The build-up process is often used in the manufacturing of printed wiring boards (PWBs) for high-density circuits. At present, CO2 laser beams are generally used in the build-up process to drill blind via holes (BVHs) that connect copper foils. However, Cu direct drilling is problematic in that it produces a copper overhang as a result of copper and resin, with different decomposition points, being melted simultaneously. Overhang could cause an adverse effect in plating the hole for connectivity. However, only few studies have investigated Cu direct processing for drilling BVHs. At an actual production site of PWBs, the number of processing holes is enormous, which leads to neglecting the quality of each processed hole. Therefore, we focused on pulse drilling, which involves laser irradiation using short multiple pulses to reduce the thermal effect. Pulse drilling could reduce overhang compared to single pulse irradiation; however, it lengthens the total processing time. Pulse irradiation after BVH formation would be unnecessary, since it could cause thermal damage to the hole and lengthen the processing time. Therefore, during pulse irradiation, it is essential to distinguish whether a BVH is formed. We observed the value of the motion graph, which was acquired from the high-speed camera images. The motion graph shows the luminance value of an image at a given time of the video. Based on the peak time of the motion graph during each pulse, we proposed a method to distinguish BVH formation during multiple pulse drilling.

In recent years, the recycling of resources has become important because of the aggravation of global environmental concerns. In light of this, it is necessary to minimize the resource needs of current production systems. This concept is called sustainable development. When this concept is applied to machine tools, the assumption is that small parts should be processed using small machines. Additionally, the diversification of consumer needs and the ephemeralization of product life cycles are progressing in industry. As a result, the overall production system has changed from high-mix low-volume production manufacturing, to variant types in variable quantity. In this background, the cell production system is receiving attention as a production system that can achieve variant types in variable quantity. The cell production system also requires miniaturization and process consolidation of machine tools, which has given rise to the need to consolidate heat treatments, especially as part of the process consolidation of machine tools. Laser beams have proved to be effective heat sources when integrated into heat-treatment processes, such as quenching and tempering on machine tool tables. On the other hand, In the case of the thin plate, it is well known that the deformation of a plate occurs due to laser irradiation, as named a laser forming. The laser forming is also effective to generate the complex shape without a press die set. Thus, we propose that the hybrid process of laser heat treatment and forming of thin plate with a small power semiconductor laser, and demonstrate that the proposed method makes it feasible to generate the hardened sheet metal products with a compact machine tools. Moreover, considering the power consumption in laser quenching and forming process, we investigate an appropriate laser irradiation condition from a view of reducing the environmental burden.

There has recently been an increasing demand for miniaturization and multi-functionalization of electronic equipment due to developments in information technology (IT). The semiconductor package printed wiring boards (PWBs) used in the central processing units (CPUs) of various electronic devices have brought about many advanced features. While the micromachining of Si wafers and integrated circuits has improved, advanced processing technologies for micro-drilling in PWBs are also required. Consequently, demands have been made to miniaturize PWBs and fabricate highly dense electrical circuit layers. To make these demands a reality, it has been necessary to decrease the diameter and distance between the wall surfaces of through holes. However, problems have emerged in that the drilling tools bend and break during the drilling process, and heat occurs damage around the drilled holes after the drilling process due to the increased drilling aspect ratio between the depths and diameters of holes. Method of step-feed drilling are generally considered to be effective ways of solving these problems. However, alternation short stroke motions by the spindle axis are needed to do the step-drilling process and these motions cause various kinds of vibrations. A machine tool was constructed with a novel counter-balance mechanism on the spindle driving Z-axis and investigated a model to estimate the appropriate balance mass for the step-drilling process. The results were compared from the frequency responses of the proposed model with these from experiment, and found that vibration could be controlled with the counter-balance mechanism. The results demonstrated that the proposed vibration-proof method could reduce vibration in high-speed step-micro-drilling motions and to improve quality of the drilled holes and the efficiency of the micro-drilling process in PWB manufacturing fields.

This paper describes an approach achieving process design based on sustainability evaluation by Life Cycle Assessment (LCA). The case study focuses on quenching steel products, which was evaluated by comparing laser quenching to conventional furnace quenching based on the proposed approach. We found that the break-even point depends on production volume as one of product features. The proposed approach shows promise as a strategy for decision making in process design.

In recent years, the performance and miniaturization of portable information devices have rapidly advanced. The build-up process is often used in the manufacturing of printed wiring boards (PWBs) for high-density circuits. At present, CO2 laser beams are generally used in the build-up process to drill blind via holes (BVHs) that connect copper foils. The Cu direct-laser method is often used in this process, which irradiates laser to drill the copper foil and insulation layer simultaneously. Cu direct-laser involves a complex phenomenon because it drills copper and resin, with different decomposition points, at the same time. However, only few studies have been made in this field. This report focuses on monitoring Cu direct-laser drilling with a high-speed camera. We drilled holes with four different laser power outputs, 25 W, 50 W, 75 W, and 95 W and measured the size of the drilled holes. During the drilling process, the camera captured the emission of scattering materials in the PWBs. We have processed the images obtained from the camera to observe the scattering material. As a result, we found out that changes in the amount of scattering occur on four occasions: when the outer copper foil is drilled through, when the drilled depth reaches the inner copper foil, when the increase rate of the hole diameter is reduced, and when the inner copper foil is drilled through. Based on these results, the suitable laser irradiation time can be determined for different drilling conditions.

Recently, there has been an increasing demand for miniaturization and multi-functionalization of electronic equipments due to the developments in information technology (IT). Thus, the miniaturization of printed wiring boards (PWBs) and fabrication of highly dense electrical circuit layers are needed to realize the miniaturization and densification of the semiconductor package PWBs. Micro-drilling technology has been attracing attention to machine the electronic micro-through holes with an ultra-high-speed spindle, more than 160 krpm. However, problems have emerged; the drill tool bends and suffers breakage in the drilling process and the heat damage around the drilled hole after a drilling process occurs due to the increase in the drilling aspect ratio between hole depth and diameter. In general, a step feed drilling method is considered an effective way to solve these problems. However, short stroke alternating motion in the spindle axis is needed to do the step drilling process and its motion causes various kinds of vibration. We constructed a machine tool with a novel counter balance mechanism in the spindle driving Z-axis and investigated a model to estimate a proper balance mass for the step drilling process. We compared the frequency response results from a proposed model with the experimental ones, and discussed a control on vibration due to the counter balance mechanism. The results demonstrate that a proposed vibration proof method was found to reduce the vibration in high-speed step-micro-drilling motion and to improve the drilled hole quality and the efficiency of micro-drilling process in the PWB manufacturing fields.

Nowadays, resource saving technologies have become important because of increasing global environmental problems. Moreover, demand is increasing for the manufacturing and machining of small mechanical parts because of the downsizing of electronic mobile devices. Thus, one requirement has emerged that these small parts have to be fabricated by smaller machine tools to reduce the environmental burden. Here, when we look at the heat treatment process, it is found that most small parts are generally treated with a large size furnace as well. Therefore, we focus on compact machine tools to develop the clean and energy-saving technology in the manufacturing fields. In the present report, we consider an in-situ laser heat treatment technology integrated on the table used for compact machine tools. In particular, we perform the entire laser hardening of a small thin plate with a small power semiconductor laser, which is an attempt to harden a whole steel sheet. However, thin plates deform during the laser hardening process, which is called “laser forming.” Thus, we discuss an effective irradiation path to prevent the deformation of plates while quenching the entire plate. Moreover, considering the power consumption in the laser quenching process, we investigate an appropriate laser irradiation condition.

In order to investigate the effects of a new surface modification method, ‘the substrate quenching after coating’ on the rolling contact fatigue strength, TiN coated steel specimens and CrAlN coated steel specimens were processed by this method and the thrust type rolling contact fatigue tests were carried out for these specimens. In the process of the substrate quenching after coating, two types of quenching methods, furnace quenching and laser quenching, were used.For the furnace quenched specimens, the delamination initiation life of CrAlN coated specimen was longer than that of TiN coated specimen. This reason could be explained by the difference of the oxidisation of CrAlN and TiN in their furnace quenching process. For CrAlN coated specimens, the delamination initiation life of the laser quenched specimens was longer than that of the furnace quenched specimens. After the initiation, the delamination of the furnace quenched specimen grew much faster than that of laser quenched specimen. These...

This paper proposes a novel process strategy for micro-cutting edge fabrication. Micro-cutting edges need a hardening process for the ridgeline parts that requires abrasive resistance, as well as edge sharpness and shape accuracy, based on their applications. Micro-cutting edge shapes also vary greatly in ridgeline profile and section. The proposed method is shape fabrication after laser hardening, which easily addresses these issues. In the present paper, effects of the proposed method are discussed and the results of a demonstration test are introduced.

Manufacturing systems have been evolving to accommodate the production of various types and volumes of products, as with the flexible manufacturing system (FMS). However, with FMS, it is difficult to change the layout of a factory and to cope with any problems that may arise. Therefore, the importance of automated guided vehicles (AGVs) is increasing because AGVs can flexibly adapt to changes of equipment in a factory. However, there has not yet been much research on systems that can respond to a large number of indefinite elements. One response to this issue might be a mimetic solution, which is the application of knowledge from one field to another. We feel that knowledge of traffic engineering, dealing as it does with the transport of passengers, could be applied to the conveyance mechanisms of AGVs. This paper describes an autonomous conveyance system for AGVs based on taxi transportation strategy. The system focuses on knowledge of a flexible taxi system in traffic engineering. We chose taxis because they operate with higher flexibility in terms of traveling routes and arrival/departure points compared with railways and buses. In this study, the waiting mode of taxis was applied as AGV rules and then tested to determine the effect of the proposed system. We came up with an equation to identify the best way of determining the waiting position. Moreover, AGV collisions are of extreme importance when AGVs run for real: if a collision occurs, we have to change the factory schedule and fix the AGV. However, in the past we have never taken account of an AGV collision, and so here we do. Two assessment functions are treated: matching time, which is the period of time elapsing between when a load is received and when a load is generated, and conveyance efficiency, which is the total distance the AGV travels divided by the total distance the AGV carries the load. Results showed that the proposed system (applying the waiting strategy of taxis as AGV rules) is effective at reducing the matching time and intersection of AGVs without any decrease in conveyance efficiency.

Recently, the development of electronic devices, such as smartphones, has meant that printed circuit boards (PCBs) have become complex multi-layer ones to provide both multiple functions and be compact. Blind via holes (BVHs) connecting the layers of the multi-layer board are processed by using a CO2 laser. The many benefits of direct processing by CO2 laser include a lower disconnect of the hole position as a result of the base drilling process in the inner layer circuit pattern. Also, efficiently dissipating heat from components improves the quality of the product as digital home appliances are increasingly compact, lightweight, and thinner. Using PCBs raises the radiation performance by the addition of alumina filler at the insulated layer. However, adding alumina filler means that laser processing is difficult, processing efficiency is reduced, and debris on the surface around the drilled hole increases. We consider what causes the changes in the processing hole by changes in the alumina filler content on the basis of data on drilling phenomena gathered with a high-speed camera. We found that the insulating layer material didn’t effect the diameter of the drill hole per laser spot diameter. The cross-section processing is done in a cone initially, and the truncated cone is then processed. And, we found that the hole depth and processing overhang was reduced, and the amount of scattering increased with the amount of alumina content filler.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we propose a sustainable manufacturing system using bamboo. A method is also proposed for extracting bamboo fibers end-milled using a machining center with in-situ measurement. Bamboo fibers with highly precise shapes are efficiently acquired. Previously, we proposed the fabrication of a binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, we have not yet constructed a method to obtain the best fiber extracting and molding conditions considering both its efficiency and performance. Therefore, in this report, we investigate the influence of the length of used bamboo fiber on the characteristics of the molded products, as its length deeply affects the extracting efficiency and focuses on a degradable plastic as a standard of molded product strength.

In our previous study, we proposed a new surface modification technique by combination of ceramic coating and laser heat treatment. By applying laser heat treatment after coating, it was possible to improve the adhesive strength and substrate hardness of ceramic coated steels without compromising the film hardness. In the present research, in order to quench a larger area of ceramic coated steel uniformly and efficiently, a high power diode laser equipped with a galvano-scanner was used in the laser heat treatment process. The scanning laser irradiation conditions to achieve uniformly quenched substrates without any surface damage were investigated for three kinds of ceramic coated steels: CrAlN, TiAlN and CrN. The film hardness and adhesive strength of the laser irradiated regions were evaluated. It is shown that scanning laser quenching after coating effectively improved the mechanical properties for larger area of ceramic coated steels.

In our previous study, we proposed a new surface modification technique by combination of ceramic coating and laser heat treatment. By applying laser heat treatment after coating, it was possible t...

Non-uniformly shaped workpieces made of such materials as ceramic and cast metal can prevent higherefficiency machining from being achieved in the conventional process due to large deviation of removal stock. Therefore, this paper proposes a novel method to achieve a high-efficiency machining strategy for non-uniformly shaped workpieces using on-machine measurement. This method utilizes on-machine measurement of a workpiece placed at an arbitrary position on a machine table as a machining pre-process. The product shape is arranged in the workpiece shape, and NC program for machining is generated based on the on-machine measurement data. The proposed method can be expected to be reasonable for a largesize product that requires long machining time because of long initial setup time and air-cutting in machining. A case study using numerical experiment was carried out. The results showed that our proposed method reduced total manufacturing time including on-machine measurement.

This paper describes fabrication of a magic-mirror with an extremely small concavo-convex surface, which is invisible to the naked eye. The magic-mirror was manufactured by end-milling with a machining center on the rear of the workpiece after polishing. Incident light was radiated to the mirror surface and the reflected light was projected on a screen. The tool pass by CNC programming show up as image of magic-mirror on the screen. Analysis of the image on the screen indicated completion rate of magic-mirror surface generation. As some experimental result, the integrated magic-mirror production process on the machining center could be achieved by a novel application of on-machine magnetic abrasive finishing and ball end-milling. Moreover, it was found to possible to fabricate a magic-mirror with satiny and continuous-curvature corrugated surface.

Fundamental characteristics in the micro drilling of carbon fiber reinforced plastic (CFRP) plates are investigated in the present paper. When micro drilling with a high-speed spindle, cutting forces during drilling, such as thrust force and torque, were measured by high resolution dynamometers and drill temperature was monitored by thermography. Comparing the experimental results of CFRP with that of drilling glass fiber-reinforced plastics (GFRP) revealed some unique tendencies. The cutting forces and drill temperature increased drastically. Moreover, drill wear rapidly accelerated. The tool life of CFRP plate drilling is much shorter than that of other plates.

Demand is increasing for the manufacturing and machining of small mechanical parts. We focus on using a multi-functional desktop-sized machine tool to meet such demands because power consumption is decreased when they are machined. However, few reports have focused on heat treatment among manufacturing processes, we investigate the laser heat treatment of small parts as a highly efficient and eco-friendly method and propose in-situ heat treatment on a desktop-sized machine tool using a low-power diode laser beam. We quenched a small thin steel plate with a 30 W diode laser source. Our proposed method makes it feasible to quench a small thin steel plate and effectively reduces the power consumption of in-situ heat treatment by a desktop-sized machine tool.

Machining is often performed by a machining center using various cutting tools and conditions for different shapes and materials. Recent improvements in CAM system make it easier for even unskilled engineers to generate NC programs. In the NC program, the end-milling conditions are decided by engineers. However, engineers need to decide the order of the process, cutting tool selection, and the end-milling conditions on the basis of their expertise and background knowledge because the CAM system cannot automatically decide. Data-mining methods were used to support decisions about end-milling conditions. Our aim was to extract new knowledge by applying data-mining techniques to a tool catalog. We used both hierarchical and non-hierarchical clustering of catalog data and also used applied multiple regression analysis. We focused on the shape element of catalog data and we visually grouped ball end-mills from the viewpoint of tool shape, which here meant the ratio of dimensions, by using the k-means method. We also found an expression for calculating end-milling conditions, and we compared the calculated with the catalog values.

Recently, demand has been increasing for various kinds and volumes of manufacturing systems. Also, the importance of the Automated Guided Vehicle (AGV) is increasing because it can flexibly correspond to the change of equipment in a factory. This paper describes an autonomous conveyance system for AGV based on a taxi transportation strategy. The system focuses on knowledge of a flexible taxi system in traffic engineering. A taxi is a transport unit in a traffic system with higher flexibility in traveling routes and arrival/departure points compared with railways and buses. In the present report, the waiting mode of a taxi is applied as an AGV rule and investigated to verify the effect of the proposed system. Moreover, the effect of multi-loaded AGV on system performance such as matching time and conveyance efficiency is investigated. A numerical experiment has been conducted to evaluate them. As a result, it was found that introduction of multi-loaded AGV is effective at reducing matching time without conveyance efficiency decrease.

A conceptually novel materials design, based on crosslinked ferroelectric liquid-crystalline polymers, is demonstrated for efficient switching of a second-order nonlinear optical (NLO) response in the solid state. By controlling the molecular alignment of the NLO moieties through two-photon isomerization of azobenzene molecules, reversible isothermal photocontrol of second-harmonic generation is achieved with contrast of up to 20.

Recently, the idea of sustainable development has become more and more important. In the previous report, we focus on downsizing industrial goods and discuss the environmental load of industrial goods. As a result, by downsizing machine tools we verified that the environmental load of mother machines in making copies of themselves could be reduced. On the other hand, we verified that the environmental load of use of the machine itself increased relatively. Thus, in desktop machine tools, we verified that reducing the environmental load of use of the machine itself would increasingly become an issue in the future. In this paper, we discuss methods of using desktop machine tools from the aspect of power consumption. As a result, we verified that in cutting along the linear-axis and rotational-axis, we have to consider back clearance after cutting.

Bamboo grows faster than other renewable natural materials. Bamboo fibre, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibres end-milled using a machining centre with in-situ measurement was also proposed. Bamboo fibres with high precision shapes are efficiently acquired. Previously, we proposed the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibres extracted by a machining centre. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, when the environment changes, the characteristics of the binder-free composite are not known. If we want to use the binder-free composite, we have to know how much it is affected by the external environment for use as a mechanical object. Therefore, we investigated the changes of the characteristics at high temperature and high humidity.

In recent years, studies have been conducted about creating metal moulds using a five-axis controlled machining centre with ball end milling. Most of these reports concern the programming of CAM based on geometry. However, there have been few reports related to polish-less finished surface. Furthermore, a specular surface like a mirror and finishing under a constant angle between ball end milling and the work piece have not been investigated. Therefore, this paper deals with the gloss of the machined surface when feed rate and pick-feed rate are changed to maintain constant surface roughness considering tool run-out under the condition that the angle between the tool and work piece in contact are inclined at 15. However, by changing the combination of feed rate and pick-feed rate, various specular changes and direction of disposition of reflected light were obtained. Therefore, we suggest a new method of evaluating the gloss of these finished surfaces. Comparing results by the proposed method with ones by a glossmeter, it is clear that an appropriate ratio of feed rate and pick-feed rate is important for obtaining finished surface. Moreover, it is demonstrated that the proposed method is effective for estimating the gloss of the machined surface.

Electrical circuits of Printed Wiring Boards (PWBs) have become multi-layered. Therefore, the formation of micro-blind holes for interlayer electrical connections (blind via holes: BVH) is required. As a result, Cu-direct laser drilling is attracting attention. However, Cu-direct drilling is problematic in that it produces a copper overhang as a result of copper and resin, which have different decomposition points, being melted simultaneously. In addition, the state of PWB surface after the laser drilling is very important. However, this procedure restricts the board density that can be achieved as a result of the limited positional accuracy of the etching process. Consequently, using a Cu-direct drilling process, which does not require etching of the copper foil, to drill BVHs to connect copper foils using a CO2 laser beam has been receiving considerable attention for the next-generation high density PWB manufacturing. However, in the Cu process of generating a direct and overhang problem, there is the problem of accuracy on the substrate surface. In contrast, in-depth research on quality companies has not been performed. Thus, we observe the removal process. Furthermore, we demonstrated reduced overhang.

This paper proposes a novel manufacturing process of a fine mesh filter screen with a pulsed laser. The fine mesh filter screen, made of stainless steel, has many small diameter holes with high aspect ratio and fine pitch. In the conventional process, an electron beam drills in a vacuum. However, this is very costly because of the expensive equipment required and batch process. Therefore, a laser drilling process for small diameter hole drilling in air with higher flexibility was proposed. The post-processes after the laser drilling completed the fine mesh filter screen.

Data mining supports decision making about reasonable end-milling conditions. Our research objective is to excavate new knowledge with mining effect by applying data mining techniques to a tool catalog. We use hierarchical and nonhierarchical clustering data mining with catalog data by applying multiple regression analysis and focusing on the catalog data shape element. We visually grouped end-mills on the basis of tool shape, considering the ratio of tool shape dimensions, by employing the K-means method. We found that factors related to blade length and full length ratio are effective in for making end-milling condition decisions. These factors have not previously been singled out through background knowledge or expert knowledge, but they were noticed as a data mining effect.

In recent years, sustainable materials using natural resources have been developed to alleviate environmental problems. Bamboo has especially drawn attention because it has the fastest growth rate among various natural materials, and its fiber also has high specific strength and stiffness like glass fiber. Previously we proposed a high quality bamboo fiber extraction method with a machining center that overcame issues including lower shape accuracy and inefficiency caused by conventional extraction methods. In this paper, we implemented a fabrication of self-adhesive products using only bamboo fibers extracted with a machining center. Moreover, mechanical properties such as Young's modules and tensile strength of the product were investigated. In addition dumping characteristics were also studied. Influences of moisture rate of the products on the properties were evaluated by concerning a practical use. Finally, possibility of the product for bamboo fiber recycling in order to reduce environmental burdens in manufacturing phase was also addressed. As a result, it was found that the self-adhesive products using only bamboo fibers show some reasonable performances.

A drilling technique using micro-drills of 0.2 mm or less in diameter and a super-high-speed spindle of 160000 rpm or more has been developed for drilling ultra-micro holes in printed wiring boards (PWBs). The drilling process requires higher reliability and quality to maintain the reliability of the electrical connection between circuit layers. On the other hand, higher processing efficiency is also required in PWBs manufacturing. To maintain high productivity, drilling is normally performed using a non-step method, but heat damage called B-RING occurs around the drilled holes with this method. To solve these problems without the loss of processing efficiency, we applied the rapid-feed step-drilling cycle method. We investigated the B-RING for drilling quality and evaluated the drilling time for processing efficiency under various drilling conditions. We found that using a rapid-feed step-drilling cycle with an appropriate number of steps and feed rates ensures a higher level of hole quality and processing efficiency compared with the conventional non-step drilling.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibers end-milled using a machining center with in-situ measurement is proposed. Bamboo fibers with high precision shape are efficiently acquired. In the present report, we propose the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper forming conditions to optimize the forming process. We also made various three-dimensional shapes considering the practical applications of the formed binder-free bamboo fiber moldings.

This paper describes the laser hardening of micro-cutting edges using an on-machine heat treatment system with a YAG laser. Various laser conditions were evaluated to perform laser quenching on a machine tool without melting at the edges. We also investigated the influence of the motion accuracy of the machining center on the quenching characteristic of micro-cutting edges after laser irradiation. We clarified that we could quench both the straight and curved corner parts by arranging proper laser irradiation conditions considering the motion accuracy of the machining center.

This paper proposes a new method for correction of tool run-out on a machine tool using a laser. The shank part of the tool attached on the machine spindle is irradiated with the laser beam. The thermal stress caused by laser irradiation at the irradiated part can make a very small deformation. First, the deformation patterns based on the thermal stress are shown. Second, experiments are carried out in order to investigate the influences of laser irradiation conditions on the deformation. Finally, a few case studies are performed using a cutting tool and succeeded in reducing the tool run-out to sub-microns.

This study describes the programming of cutter location based on a constant feed-speed vector at the cutting point with a ball nose end-mill tool by a Five-axis Machining Center. In the present paper, we proposed a new programming method to maintain both feed-speed amplitude and direction at the cutting point using rotational and linear axes controlling. First of all, we focused on generating a hemispherical surface with a ball nose end-mill, and investigated its surface roughness and its profile error. As a result, it can be seen that this method is effective to obtain a fine machined surface roughness and to avoid the influence of linear motion errors on the machined profile at the normal direction to the feed-speed vector.

The inclusion of the application of the double ball bar (DBB) measurement to the accuracy calibration of five-axis machine tools into the revision of ISO standards is currently under the discussion. This paper presents the modified DBB measurement device, referred to as “DBB5” in our study, where master balls are supported from the 45°direction to the spindle axis. It can perform all the circular tests on XY, YZ, and ZX planes without changing the setup. This paper first presents the classification of motion error components of a five-aixs machine tool into location and component errors. Experimental application examples of the DBB5 to the calibration of location and component errors assciated with rotary axes on a five-axis machine tool are then presented.

This paper deals with a decision method of cutting conditions and tool life estimation method for end-milling processes of plain carbon steel. Basic cutting conditions for side cutting of a step, one of the most basic milling processes, are chosen from the database given by a cutting tool manufacturer. These data are transformed for individual milling processes, e.g. trochoidal grooving, spiral hole enlarging, and corner milling, such that constant cutting force is kept by using feedforward control. Cutting tests were conducted for the workpiece composed of various cutting features, and it was clarified that adequate cutting conditions and adequate tool life are simply decided using by this method.

In this study we attempted to suppress chatter vibration in end-milling of austenitic stainless steels with an end-mill having different helix angles. We showed there were two types of chatter vibration in end-milling with a conventional end-mill with regular helix angle. The two types of chatter vibration depend on the cutting speed. We detected these two types of chatter vibration by the developed monitoring method using laser Doppler vibrometers. We classified the two types of chatter vibration according to chatter generating tendency, frequency and vibration mode. We showed that chatter vibration generated at lower cutting speeds was regenerative chatter vibration. On the other hand, chatter vibration generated at higher cutting speeds was another type. We showed that a end-mill with different helix angles could prevent generative chatter vibration at lower cutting speeds and was also effective in suppressing chatter vibration at higher cutting speeds.