bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Cam-Drive Type Proportional Valve for Water Hydraulics
Authors: Suzuki Kenji ,   Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan, Akazawa Sho , Nakao Yohichi
Published: April 2016

This paper describes the development of water hydraulic proportional valves. These valves are spooltype and the spool is driven by a positive cam mechanism with an appropriate motor, such as a stepping motor or servo motor, depending on the application. The cam is placed precisely between two cam followers so that no gap is left between the cam and followers. Accordingly, no return spring is required. The rotational angle of the cam and the displacement of the spool are linear. Mathematical models of static characteristics of the valves are derived. Experimental results for the static characteristics are also shown: internal leakage and pressure gain against spool displacement, flow rate characteristics with no load, and flow rate against load pressure. Although the spool overlaps with sleeve, no dead band was observed in flow rate characteristics with no load because of leakage passing through the clearance around the spool. In addition, the nonlinearity of spool displacement against the rotational angle of the cam was below 0.2% and hysteresis was hardly observed. Feedback control of the displacement of water hydrostatic bearings is conducted as an application of the developed valve.
Analysis of Velocity Control Performance and Energy Recovery Efficiency of Water Hydraulic Fluid Switching Transmission
Authors: Pha Pham Ngoc ,   Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-city, Saitama 337-8570, Japan, Ito Kazuhisa , Kobayashi Wataru , Ikeo Shigeru ,   Department of Engineering and Applied Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan
Published: April 2016

Beside various fluid power transmissions, a new water hydraulic Fluid Switching Transmission (FST) has demonstrated outstanding advantages such as environmental friendliness, safety, running cost reduction, and lower energy loss for using only ON/OFF valves. Especially, this system has no servo or proportional valve; thus, lower power transmission loss can be expected. In this paper, two most important aspects of the FST system, velocity control and energy saving performances, will be presented. First, the error of the load rotational velocity is mainly influenced by property of ON/OFF valves, velocity transducer, and control logic. The research solved the problem – how to reduce the percentage error of velocity control. The experimental results showed that the error could be reduced to less than 3% for all given reference speeds equal or above 800 revolutions per minute (min-1). Second, the system regenerated the kinetic energy of the load by storing it into an accumulator during deceleration phase. This energy will be reused as the second driving source in the next cycle. By this way, 26-36% of the kinetic energy can be saved corresponding with the reference velocities. Furthermore, to reduce energy consumption, a method to control electric motor was also proposed and shown that the energy consumption reduced drastically – more than 50%.
Concept of a Focus-Tunable ECF Microlens and Fabrication of a Large Model Prototype
Authors: Kim Joon-Wan ,   Tokyo Institute of Technology, R2-42, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan, Yoshimoto Takashi , Yokota Shinichi , Edamura Kazuya ,   New Technology Management Co. Ltd., 2-9-1-306 Higashi-Shinkoiwa, Katsushika-ku, Tokyo 124-0023, Japan
Published: April 2016

This paper proposes a novel elastomer-based tunable liquid-filled microlens by using an Electro-Conjugate Fluid (ECF) jet and MEMS technology. The common approach for tuning an elastomer-based microlens is to change the geometry of the boundary determined by the control pressure of the chamber by using an external pump. However, this paper proposes placing the ECF micropump inside the tunable microlens. The ECF is a dielectric fluid that works as a smart fluid, generating a powerful jet flow (ECF jet) when subjected to a high DC voltage. Since the ECF jet is generated only with a pair of tiny electrodes, the pumping mechanism can be easily inside the device. We fabricated the large model prototype of an ECF focus-tunable microlens by partially utilizing MEMS technology. The experimental results showed us the feasibility of the ECF microlens.
Flow Analysis in Pipe of a Manifold Block
Authors: Abe Osamu ,   Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan, Tsukiji Tetsuhiro , Hara Takeshi , Yasunaga Kazutoshi ,   TOKYO KEIKI INC., 1-1 Sakae-cho, Sano-shi, Tochigi 327-0816, Japan
Published: April 2016

Manifold blocks are recently used to connect hydraulic components in hydraulic system, which has flow channel inside. They are useful for reducing the size and weight of hydraulic systems. This paper deals with solid manifold block and laminated manifold block. They are different from machining. We investigate pressure drops of their pipe flow with Computational Fluid Dynamics (CFD) and compare those of two types. And then, we conduct experiment, measuring pressure and visualization, to validate the results of CFD analysis. By using these results, we are intended to obtain guidelines for pipeline design in laminated manifold block.
Proposal of a Mechanism to Restrict Pressure Change by Oil Temperature Change
Authors: Sakurai Yasuo ,   Ashikaga Institute of Technology, 268-1 Oomae-cho, Ashikaga-shi, Tochigi 326-8558, Japan, Suzuki Takayuki , Aiba Kenichi , Yoshinari Takamasa , Kawashima Kiyotaka , Kihara Kazuyuki ,   Bosch Rexroth Corporation, 5-1 Higashi-nakanuki-cho, Tsuchiura-shi, Ibaraki 300-8588, Japan,   Tokyo Keiki Corporation, 1-1 Sakae-cho, Sano-shi, Tochigi 327-0816, Japan,   Industrial Property Cooperation Center, 1-2-15 Kiba, Koto-ku, Tokyo 135-0042, Japan
Published: April 2016

One of the advantages of an oil-hydraulic system is that it keeps the value of its oil pressure when the pressurized oil is enclosed in a container. However, when the temperature of the oil changes, it is impossible to keep the value. If a pressure-control sub-system is used to prevent the pressure change, the whole system becomes complicated. In addition, energy is consumed when the pressure is adjusted by the quantity of oil flowing in or out of the container. From these view points, it would be useful if a component were developed which prevented the pressure change caused by the change in oil temperature without controlling the quantity of oil. Therefore, in this paper, a mechanism to prevent the pressure change caused by the oil temperature change is proposed to secure the advantages of the oil hydraulic system even when the temperature of the oil changes. And a component is fabricated to investigate the validity of the proposed mechanism. Its validity is investigated experimentally when the temperature of the oil increases and when the temperature of the oil decreases after it increases.
High Precise Milling Process by cBN End Mills
Authors: Naganuma Katsumi ,   NS Tool Co., Ltd., 4-5-9 Minamioi, Shinagawa-ku, Tokyo 140-0013, Japan, Mori Masato
Published: April 2016

Molding technology is one way of producing the micro-precision parts required by various industries. To Advance this molding technology, various elemental technologies related to materials, construction and machiningmethods are evolving together. One of these elemental technologies is milling by end mill. Further research and development of end mill is underway in response to improvement and requirement of molding technologies. There are various demands for end mills such as improvement of tool life and stable machining quality. Here we report the small diameter cBN end mill, developed as a tool to provide with stable machining accuracy with long tool life for high hard materials. We report the investigations and characteristics at the time of development and show the machining test.
A Study of Nanometric Surface Generation on Tungsten Carbide Using a Micro Polycrystalline Diamond End Mill
Authors: Nakamoto Kazuo ,   School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama, Kanagawa 223-0061, Japan, Aoyama Tojiro , Katahira Kazutoshi , Fonda Peter , Yamazaki Kazuo ,   Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama-shi 223-8522, Japan,   Senior Scientist, Materials Fabrication Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan,   IMS-Mechatronics Laboratory, University of California, Davis, One Shields Avenue, 2132 Bainer Hall, MAE Department, Davis, CA 95616, USA,   University of California, 5136 Etcheverry Hall, Berkeley, CA 94720-1740, USA
Published: April 2016

The demand for high quality micro-scale molds for the production of high value-added miniature parts is rapidly growing. The fabrication of such molds requires highly productive and high quality micro milling of hard and brittle materials, such as tungsten carbide (WC). Such micro milling processes have not yet been studied well, however, so their fundamental nature is not yet well understood. This paper reports the results of a study on the basic nature of the micro milling process when WC is machined with a custom made PCD (poly-crystalline diamond) micro tool. The study includes the design and fabrication of a custom micro end mill tool with a single cutting edge, experimental procedures to find the optimal machining conditions for high quality surface generation, and an evaluation of the quality of the machined surface in relation to tool wear. The results of the experimental study indicate that machining conditions exist for the generation of a surface with nanometer-level roughness. Normal tool wear is maintained over long cutting lengths while tool wear grows continuously on the axial clearance face of the end mill.
Design Method for Inner Structure of Injection Mold Fabricated by Metal Laser Sintering
Authors: Koresawa Hiroshi ,   Department of Mechanical Information Science and Technology, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502, Japan, Fukumaru Hirofumi , Kojima Michio , Iwanaga Jun , Narahara Hiroyuki , Suzuki Hiroshi
Published: April 2016

This paper discusses design methods for the internal structure of molds used in production utilizing metal laser sintering combined with high speedmilling which selectively sinters metal powder to form a three dimensional mold. This milling technique is characterized by the fact that the selective laser sintering process and milling process are carried out in alternating sequence, achieving the level of processing accuracy demanded of mold production. In addition, in the selective laser sintering process, because the mechanical strength of the sintered body (Young’s Modulus) is variable, suitable interior structures that consider dynamic conditions are expected. However, in the current state of design, this structure is determined experimentally, and there is a high possibility of incurring unnecessary production time and high costs. In this paper, we investigate a method that incorporates an optimization method using stress that occurs within the structure interior, obtains the interior topological structure as a Young’s Modulus distribution, and designs a suitable interior structure using this distribution. As a result of investigation using numerical analysis, we obtained a structure that reduces the volume of the sintered body, having high mechanical strength in comparison with a conventional structure while improving structural rigidity.
Reducing Weld Line by Heating Mold Surface with Heater Embedded by Laser Metal Sintering
Authors: Yoneyama Takeshi ,   School of Mechanical Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan, Abe Satoshi , Miyamaru Michiru ,   Panasonic Corporation Eco Solutions company, 1048 Kadoma, Osaka 571-8686, Japan,   Miyamaru Precision Mold Co., 1-31 Higashi-kayatsume, Kanazawa 920-0209, Japan
Published: April 2016

Thin micro sheath heaters are embedded just under the surface of a mold during the process of laser metal sintering. This is to reduce the weld line on the molded surface by heating it just before the injection. Laser metal sintering process was interrupted at a level just below the final height to make grooves into which to insert micro sheath heaters. After the heaters were installed, laser metal sintering continued over the heaters until the final mold height was reached. Through this process, micro heaters 1 mm in diameter were embedded 2 mm under the mold surface. The mold surface was heated to 20°C over the cooling temperature by the embedded heaters just before the injection, and heating was stopped after the injection. By so doing, the weld line on the molded surface was reduced, while the cooling time was the same as in molding without such heating.
Synthesis of Porous Titanium with Directional Pores by Selective Laser Melting
Authors: Nakamoto Takayuki ,   Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi-shi, Osaka 594-1157, Japan, Shirakawa Nobuhiko , Kishida Kyosuke , Tanaka Katsushi , Inui Haruyuki ,   Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan,   Department of Mechanical Engineering, Kobe University, Nada-ku, Kobe 657-8501, Japan
Published: April 2016

There has been a growing interest and practical importance in producing implants such as artificial joints, bone fixators and spinal fixators with titanium. In order to achieve good bone/implant fixation while avoiding the problem of bone absorption, it is mandatory to reduce the Young’s modulus of titanium while keeping the high strength so as to achieve the compatibility in these mechanical properties with human cortical bone. We have tried to fabricate porous titanium with directional pores by the use of the method based on Selective Laser Melting (SLM), in which complex three-dimensional parts even containing designed shapes of pores can be produced by sintering successive thin layers of metal powder with a laser beam. Here we show that porous titanium with directional pores aligned in the longitudinal direction of the ingot is successfully produced through the use of the SLM process and that high strength and low modulus comparable to those of human bone are simultaneously achieved when these properties are measured in the longitudinal direction of the ingot.
Cutting Path Design to Minimize Workpiece Displacement at Cutting Point: Milling of Thin-Walled Parts
Authors: Koike Yusuke ,   Kyoto University, Yoshidahonmachi, Sakyo-ku, Kyoto-shi, Kyoto 606-8501, Japan, Matsubara Atsushi , Nishiwaki Shinji , Izui Kazuhiro , Yamaji Iwao
Published: April 2016

Vibrations of a tool or workpiece during cutting operations shorten tool life and causes unwanted surface roughness. In this report, we propose an algorithm for determining the sequence of material removal, tool orientation, and feed directions, an algorithm minimizes workpiece displacements by considering workpiece stiffness and cutting force. In this research, the cutting path consists of the material removal sequence, tool orientation and feed directions. The material removal sequence changes the workpiece compliancematrix at the cutting points, and the feed directions and tool orientation change the direction of the cutting force. In our algorithm, workpiece displacements are reduced by changing the material removal sequence and applying the cutting force in the direction of higher workpiece stiffness. A numerical example demonstrates how the algorithm obtains appropriate cutting paths to mill a cantilever form. In the numerical example, three optimized cutting paths are compared with an unoptimized cutting path, a path used by an expert and based on the expert’s personal experience, to machine a low-stiffness workpiece. The obtained material removal sequence of the minimax compliance path is almost the same as that of the unoptimized cutting path. Workpiece displacements at the cutting point of three optimized cutting paths are approximately 10% smaller than those of the unoptimized cutting path. The minimum displacement path is the best of these three optimized cutting paths because fluctuations in workpiece displacements at cutting point are the smallest. These optimized cutting paths show the cutting path strategy as a rough cutting path for machining the thin-walled cantilever.
Tool Posture Planning Method for Continuous Multi Axis Control Machining with Consideration of Shortening Shank Length of End Mill
Authors: Kaneko Jun’ichi ,   Production and Processing Laboratory, Saitama University, 255 Shimo-Ohkubo, Sakura-Ku, Saitama City, Saitama 338-8570, Japan, Horio Kenichiro
Published: April 2016

In recent multiaxis-controlled machine tools, a new planning method to keep continuous motion on rotational axes and tool setting with short shank length from tool holder end is required to realize both high productivity and fine surface. This paper propose a new planning method consisting of a temporary search of new tool posture based on estimation of the required shank length and the gradual optimization process of motion on rotational axes. The proposed method repeats the following three planning steps: the estimation of interference between the cutting tool and workpiece, the search for a new tool posture to avoid interference and the re-planning of tool posture changes to prevent rapid motion on rotational axes. By repeating these steps many times, continuous change can be gradually realized in rotational axes without interference.
Contour Tracking of Soft Sheet Materials Using Local Contour Image Data
Authors: Osawa Fumiaki ,   Department of Electrical and Electronic Engineering, Daido University, 10-3 Takiharu-cho, Minami-ku, Nagoya 457-8530, Japan, Kano Kazunori
Published: April 2016

Technologies related to the handling of cloth products still rely on human hands in the apparel industry and in the fields of medicine, welfare, and nursing care; hence, the automation of these technologies is strongly desired. However, the cloth material in question is characteristically non-linear and anisotropic, so it is not easy to predict its dynamic deformation. Therefore, no guidelines for integrated methods of using robots to handle cloth material have been established. In this paper, we propose a method of tracking the contour of a piece of cloth that has curved edges. The aim of the method is to spread soft, flat objects of different shapes, such as clothes. We show contour extraction performed by a camera mounted on a fingertip of a robot hand and operational plan of a manipulator on the basis of the extracted information. The effectiveness of the method is demonstrated by extracting the contour of a piece of patterned cloth, controlling the hand direction and the depth of grasp, and tracking the contour of a piece of cloth with partly curved edges.
Real-Time Cutting Force/Torque Prediction During Turning
Authors: Enomoto Kazuto ,   School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan, Takei Masaya , Kakinuma Yasuhiro
Published: April 2016

The automation of machining processes requires highly accurate process monitoring. However, the use of additional sensors leads to a significant increase in the cost and reduces the stiffness and reliability of mechanical systems. Hence, we propose a system called the cutting force observer, which uses a sensor-less and real-time cutting force estimation methodology based on the disturbance observer theory. Monitoring methods using the cutting force observer may enhance the productivity during turning. One of the parameters that significantly affect the cutting process is the shear angle. The determination of the shear angle is very important as it can be used for identifying the machining conditions. In this study, an external sensor-less monitoring system of the shear angle during turning is developed, and its performance is evaluated.
Toolpath Generation Method Based on Control Characteristics of Machine Tool for High-Speed and High-Accuracy Machining
Authors: Saito Kosuke ,   Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama 223-8522, Japan, Aoyama Hideki , Sano Noriaki ,   UEL Corporation, 33-8 Wakamatsu, Shinjuku, Tokyo 162-0056, Japan
Published: April 2016

Drive control of NC machine tools is based on linear interpolation. When curved surfaces are machined using linear interpolation, problems arise with the feedrate not reaching the command feedrate, machining accuracy and surface quality decreasing, etc. In order to solve such problems, a method for generating a toolpath based on the control characteristics of a machine tool is proposed. The effectiveness of the proposed method is confirmed through simulations and experiments. It is found that the proposed method can reduce the cutting time to approximately 50% of the time required when conventional CAM systems are used. The proposed method also improves surface quality.
Fast Detection of Chatter in End-Milling Using Pseudo Auto-Correlation Function
Authors: Shimana Kenji ,   Kagoshima National College of Technology, 1460-1 Shinko, Hayato-cho, Kirishima-shi, Kagoshima 899-5193, Japan, Kondo Eiji , Karashima Hiroko , Kawagoishi Norio ,   Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan,   Daiichi Institute of Technology, 1-10-2 Kokubuchuo, Kirishima-shi, Kagoshima 899-4395, Japan
Published: April 2016

The chatter vibrations cause problems, such as the reduction of tool life, tool fracture, and a deterioration in the quality of the machined surface. This paper presents a fast detection method for expected chatter in high-speed end-milling. In this study, a pseudo auto-correlation function is applied to tool vibration data sampled at intervals as the spindle rotated at a constant angle. The calculation time for the pseudo auto-correlation function is expected to be shorter than that of the FFT method. As a result, it was indicated that detection reliability under the proposed method was approximately equal to the detection reliability by the previous methods by using tool vibration data sampled at constant intervals of time.
A Multiple Level of Detail Approach to the Tactical Movement Problem
Authors: Beasley Peter ,   School of Mechanical of Mining Engineering, University of Queensland, Brisbane 4072, Australia, McAree P. Ross
Published: April 2016

The tactical movement problemis considered to be one in which a robotic agent is required to move around its world to complete a task. This agent has manipulation abilities which allow it to perform work on its local surroundings. The coupled optimisation of the agent movements and manipulations is thus of key importance to minimise the cost of completing the task. The driving practical application in this paper is one of cost effective excavation in a mining environment. The agent is a mining shovel and it has the ability to manipulate the world through excavation actions. The problem becomes one of determining the optimal path that the shovel should take and the dig operations that should be completed at each point along the path. An initial solution is presented to automatically generate an optimized dig plan for a large robotic excavator. A wavelet based detail reduction approach is used which allows a near optimal solution of the problem to be generated in practically useful timeframes.
Application of Automated Context-Based DSS for Determining CNC Machining Parameter
Authors: Sakarinto Wikan ,   Diploma Program of Mechanical Engineering, Gadjah Mada University, Jl. Yacaranda, Sekip Unit IV, Yogyakarta 55281, Indonesia, Wibowo Setyawan Bekti , Narazaki Hiroshi , Shirase Keiichi ,   Production System Laboratory, Kobe Steel, Ltd, 5-5 Takatsukadai 1-chome, Nishi-ku, Kobe 651-2271, Japan,   Department of Mechanical Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokko-dai, Nada, Kobe 657-8501, Japan
Published: April 2016

This paper describes the implementation of proposed KBS automatically aware of context or constraints in which the user has to deal with to come up with intelligent DSS. Context is a fundamental information resource that has to do closely with the use of knowledge. The proposedKBS is equipped with the Expert System (ES) providing Decision Support System (DSS), aimed for realizing effective utilization of captured CNC operator knowledge when they assess machining parameters within product data. The newest module in the proposed KBS is equipped with automated contextbased DSS constructed from incoming task restraints and other related machining aspects, such as machining parameter values, cutting tool, workpiece material, etc. In this work, the discussions are focussing on CNC milling operations. According to the implementation result, CNC operators have shown enhanced accuracy on defining machining parameter values with respect to specific constraints.
Workpiece Fixture Planning Method for Continuous Multi-Axis Machining with Consideration of Motion on Translational Axis
Authors: Kaneko Jun’ichi ,   Production and Processing Laboratory, Saitama University, 255 Shimo-Ohkubo, Sakura-Ku, Saitama City, Saitama 338-8570, Japan, Horio Kenichiro
Published: April 2016

This study deals with a new method to plan fixture conditions of a workpiece on a trunnion table in a continuous multi-axis-controlled machine tool. The motion of the translational axes on the machine tool is usually greatly affected by machine tool structure, tool posture change, and the fixture conditions of the workpiece. However, in a conventional CAM scheme, the fixture conditions are designed to be determined separately. Furthermore, a method of planning these conditions to reduce total machining time has not been proposed. Therefore, this paper proposes a new planning method for workpiece position and posture on a trunnion table. The proposed method consists of two different steps. In the first step, a large number of fixture condition candidates are assumed automatically. In the second step, geometric calculations are executed to estimate the distribution of features in terms of motion on the translation axes. The second step is equivalent to the repetition of coordinate transformations in the conventional post process software. In the developed prototype system, parallel processing technology known as GPGPU is introduced to drastically reduce calculation time. The developed system can visualize differences in total travel distance, maximum velocity, and total machining time for each candidate. These results can assist a CAM operator in selecting the optimal fixture conditions in a short time.
Micro Hole Piercing for Ultra Fine Grained Steel
Authors: Komatsu Takafumi ,   Komatsuseiki Kosakusho Co., Ltd., 942-2 Shiga, Suwa-city, Nagano 392-0012, Japan, Kobayashi Hitoshi , Torizuka Shiro , Nagayama Shin-ichi ,   National Institute for Material Science, 1-2-1 Sengen, Tsukuba-city, Ibaraki 305-0047, Japan,   Tokushu Kinzoku Excel Co., Ltd., 56 Tamagawa, Tokigawa-machi, Hiki-gun, Saitama 355-0342, Japan
Published: April 2016

Ultra fine grained steels have been developed by many researchers. However, studies on the effects of different grain size on processes and product functions have been limited because the size of the bulk material has been small for these products. The authors have developed a production process for thin ultra fine grained stainless steel coil, and the effects have been clarified. This paper first reports the effects onmicro hole piercing by comparing materials with different grain sizes. Secondly, orifices are produced from these materials, and the liquid flow volume is measured as the functional effect of different grain sizes.
Simulation Technologies for the Development of an Autonomous and Intelligent Machine Tool
Authors: Shirase Keiichi ,   Graduate School of Engineering, Kobe University, 1-1 Rokko-dai, Nada, Kobe 657-8501, Japan, Nakamoto Keiichi ,   Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
Published: April 2016

An autonomous and intelligent machine tool have been developed to solve fundamental issues with the current command method using NC programs, and simulation technologies for its realization have been introduced. The process planning system introduced here, various process plans can be created, and the best process plan can be selected to achieve flexible machining operations in accordance with changes in production planning. Digital Copy Milling, digitizing the principle of copy milling, has opened up new possibilities for machine tool control. The NC machine tool can be directly controlled with the 3D CAD data of the product shape in Digital CopyMilling. Direct machining without the need to create an NC program before milling operation, adaptive control which changes the cutting conditions in accordance with the cutting load during milling operation, and fault detection in the cutting load and avoiding tool breakages can be performed through Digital Copy Milling. Themilling process simulator with integrated milling shape simulator and cutting force simulator provides new functions. Simultaneous cutting force prediction with milling operation provides the possibility of milling process control and fault detection by comparing the measured cutting force with the predicted one.
Collision Avoidance of a Welding Robot for a Large Structure (Application of Human Experience)
Authors: Asakawa Naoki ,   Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan, Kanjo Yoshihiro ,   Turumi-Works, JFE Engineering Corp., Suehiro-chou, Turumi-ku, Yokohama-city, Kanagawa-pref, Japan
Published: April 2016

The study deals with the automatic generation of a program with collision avoidance for a welding robot for a large structure. An industrial robot used for welding large structures must consider collisions between the tool and workpiece, the robot arm and workpiece, and with surrounding objects. In the study, the experiences of skilled workers are used to consider collision problems while generating a robot control program. Through the experiment, the system was found to have the ability to resolve collision problems.
Single-Side Resistance Spot Welding Process for Joining Pipes and Sheets
Authors: Nishibata Hitomi ,   Sumitomo Metal Industries, Ltd. (Now at Nippon Steel & Sumitomo Metal Corporation), 1-8 Fuso-cho, Amagasaki, Hyogo 660-0891, Japan, Kikuchi Shota , Fukumoto Manabu , Uchihara Masato
Published: April 2016

This paper describes a Single-Side resistance Spot Welding (SSSW) process which is expected to be a productive welding technology for the joining of stamped sheet panels to hollow parts for auto bodies. To obtain guidelines for making a sound weld with the SSSW process, the effects of welding parameters and the alignment of specimens on nugget growth are investigated experimentally. In addition, a numerical study is carried out to discuss the mechanism of nugget growth in the SSSW process.
Improving the Measurement Reliability of the End Gaps of Piston Rings
Authors: Fu Luhua ,   State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China, Zhang Heng , Sun Yan , Zhao Na , Wang Zhong ,   National Institute of Metrology of China, Beijing 100013, China
Published: April 2016

By using an automatic piston ring separator based on advanced computer vision detection technology, the end gaps of piston rings can be automatically measured with high efficiency and accuracy. To get a complete and accurate image of the end gap as well as measurement reliability, the positioning of the end gap of a piston ring must be accurate every time it is photographed. During the loading process, a mechanical structure and pneumatic actuators are used to provide the correct initial position and guide the motion. The actuators also control the deflection of the piston ring and get the top surface levels of the piston rings evened up at the detection position to ensure the correct detection position and imaging object plane. This guarantees the quality of the images of the end gaps. Data compensation is carried out to decrease the system errors arising from manufacturing errors in ring gauges and increasemeasurement accuracy. Experimental results show that the measurement accuracy meets the demands well, and measurement reliability is good.
Collision Avoidance of a Welding Robot for a Large Structure (Application of Potential Field)
Authors: Asakawa Naoki ,   Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192, Japan, Kanjo Yoshihiro ,   Turumi Works, JFE Engineering Corp., Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa 230-8611, Japan
Published: April 2016

This study deals with the automation of welding by generating control commands for a welding robot automatically. Generally, a movement of a robot is decided depending on the tool path – a series of positions and postures of the tool attached to the mechanical interface of the robot. We tried to generate the tool path focused on the collision avoidance of the welding tool on the basis of CAD data on the workpiece. In the study, to cope with a characteristic of welding, the requirement to be continuous in tool velocity and posture, the tool path is generated through the use of a potential field in a configuration space. As a result, the system is found to successfully generate smooth and collision-free tool paths.
Acoustic Emission Based Tank Bottom Floor Corrosion Detection
Authors: Zhang Tao ,   State Key Laboratory of Precision Measurement Technology and Instrument, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, P.R.China, Feng Hao , Zeng Zhou-Mo
Published: April 2016

The tank bottom floor is a crucial component of large oil storage tanks, and its status has a pivotal impact on the integrity of the entire tank. Acoustic Emission (AE) monitoring is an advanced, in-service, nondestructive testing method internationally recognized to be capable of assessing the tank bottom floor without the necessity of prior tank cleaning. In this paper, the principle of Time Difference of Arrival (TDOA) is illustrated, and the efficiency of piezoelectric AE sensors is verified through a field experiment. The authors then investigate Mach-Zehnder interferometerbased AE sensors with a view to using optical fiber sensors as a substitute for acoustic emission detecting. The results of the experiment indicate that optical fiber AE sensors based on the Mach-Zehnder interferometer can be used as transducers sensitive to acoustic events, so they can serve as indicators of the imminent failure of a structure. In addition, some suggestions are put forward regarding forthcoming actual application.
Identification Method of Dynamic Characteristics of Joints in Jointed Structures
Authors: Shimizu Shinji ,   Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, Japan, Kabaya Yoshiaki , Sakamoto Haruhisa , Yamashita Kenichi ,   ISUZU Advanced Engineering Center, Ltd., 8 Tsutidana, Fujisawa, Kanagawa, Japan
Published: April 2016

In this paper, we propose a method of identifying the dynamic characteristics of joints in jointed structures. We first consider a joint model for finite element analysis. We then propose, based on the consideration, a method of identifying dynamic characteristic parameters of the joint, such as the spring stiffness and damping coefficient, with the joint model. As a result, we obtain a joint model with the spring and damping elements in vertical and tangential directions between a pair of nodes with changeable numbers and locations. The number and location of these elements can be determined so that the vibration mode and the inertance transfer function of the jointed structure obtained from finite element analysis with infinite stiffness of the spring element agree with those of the structure without joints. In addition, we identify the dynamic characteristic parameters of the joint so the experimental inertance transfer function and vibration mode agree with those obtained from the finite element analysis.
The Statics Analysis and Verification of 3-DOF Parallel Mechanism Based on Two Methods
Authors: Lu Guangda ,   Tianjin Key Laboratory of Information Sensing and Intelligent Control, Tianjin University of Technology and Education, Dagunanlu 1310#, Hexi district, Tianjin, 300222, China, Zhang Aimei , Zhou Jing , Cui Shigang , Zhao Li ,   Tianjin ALSTOM Hydro. Co., Lt., Gaofeng Road 2600#, Beichen District, Tianjin, 300000, China,   Hebei University of Technology, Dingziguyihao Road 8#, Hongqiao District, Tianjin, 300130, China
Published: April 2016

Statics of the 3-RSS/S parallel ankle-rehabilitation robot is analyzed in this paper using two methods, i.e. the component vector method and the principle of virtual work. Static equilibrium equations based on component vector theory were established on a moving platform, and cranks of 3-RSS/S parallel Ankle-rehabilitation Robot, using this method, to obtain mathematical relationships between the external torque of moving platform and the output torque of three cranks. The velocity Jacobian matrix of the robot is calculated firstly using the principle of virtual work method, then the force Jacobian matrix is obtained based on the relationship between velocity Jacobian matrix and force Jacobian matrix. The results of the two methods are verified and found to be consistent by calculation, and the force Jacobian matrix of the robot is the basis of the force feedback control for the Ankle-rehabilitation Robot.
Applying Constant Pressure Unit to Ductile Mode Cutting of Hard and Brittle Materials
Authors: Kuriyama Kunitaka ,   Toshiba Machine Co., Ltd., 2068-3 Ooka, Numazu, Shizuoka 410-8510, Japan, Fukuta Masahiko , Sekiya Katsuhiko , Yamada Keiji , Yamane Yasuo ,   Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
Published: April 2016

It is strongly wished that hard and brittle materials could be used in a wide variety of fields because of their great material characteristics. For now, however, minute profiling or high-efficiency cutting of these materials has not yet been put into practice due to their hardness. At the same time, there have been numerous reports available on ductile mode cutting for hard and brittle materials in response to the increasing demand. Very smoothly finished surfaces can reportedly be generated through the work of a material removal mechanism similar to plastic deformation, done by microminiaturizing cutting units with the sharp cutting edges of tools. Because of the extremely narrow ductile mode regions, however, forced cutting processing, which includes cutting work, demands extremely high motion performance or rigidity of machine tools, and this makes it difficult to realize stable ductile mode cutting. On the other hand, pressure cutting processing similar to polishing is known to be capable of producing extremely smooth finished surfaces on hard and brittle materials; this suggests that we could realize stable ductile mode cutting that will always create the same depths of cut by controlling the insertion forces on the tools. In this paper, in order to realize stable ductile mode cutting, we have devised and prototyped a constant pressure cutting device which can regulate cutting forces by regulating supply pressure with air static pressure bearings. We have investigated the relationships between the pressure supplied in the cutting direction and the cutting forces in order to get static pressure characteristics of the prototype device. We have also carried out experiments to cut hard and brittle materials with the prototype constant pressure cutting device mounted on the tool post of an ultraprecision machine tool to prove the effectiveness of the constant pressure cutting device for the ductile mode cutting of hard and brittle materials.
Cutting Characteristics of CFRP Materials with Carbon Fiber Distribution
Authors: Inoue Takashi ,   Department of Mechanical Engineering, Daido University, 10-3 Takiharu-cho, Minami-ku, Nagoya 457-8530, Japan, Hagino Masahiro ,   Department of Material and Environmental Engineering, Daido University, 10-3 Takiharu-cho, Minami-ku, Nagoya 457-8530, Japan
Published: April 2016

This study details the machinability of CFRP materials with fiber orientation set Quasi-isotropic in the orientation of (0°, 45°, 90°, -45°), plain weave type in the orientation of (0°, 45°) and at random in using High-Speed Steel (HSS), Nitride HSS, Tungsten-Carbide, TiAlN-coated tungsten carbide and Poly-Crystalline Diamond (PCD). The influences of cutting distance, cutting force, cutting temperature and tool wear on the surface characteristics of the CFRP materials are also examined. The results of our experiments reveal that the cutting force and cutting temperature increases when cutting randomly-orientedmaterials irrespective of the type of cutting tool used. The increment of the cutting force obtained was about 5% compared to cutting plain weave type oriented materials. In addition, the cutting temperature of the central portion was 20°C higher than the surface temperature. The tool wear of straight-edge type PCD tools was about 0.1 mm at 30 m cutting distance, whereas, at sharp edge, and lead angle of 30°, the tool wear reached 0.1 mm at 9 m cutting distance. Additionally, the straight-edge type cutting tool showed better results with respect to adhesion of coated materials.
Machining of Inconel 718 with Lubricant-Coated Tool
Authors: Usuki Hiroshi ,   Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu-cho, Matsue-shi, Shimane 690-8504, Japan, Uehara Kazutake , Isaka Masakazu , Kubota Kazuyuki ,   Yasu Plant R&D, Hitachi Tool Engineering, Ltd., 35-2 Mikami Yasu-shi, Shiga 520-2323, Japan,   Narita Plant R&D, Hitachi Tool Engineering, Ltd., 13-2 Shin-izumi, Narita-shi, Chiba 286-0825, Japan
Published: April 2016

Cutting tools coated with TiBON films of different boron concentrations and thicknesses are made, and then the effects of boron concentrations and coating film thicknesses on tool wear are investigated in turning and milling of Inconel 718 under dry cutting conditions. Results show that the tool coated with the film that has a boron concentration of 15% has the longest tool life, about four times longer than that of a tool coated with a single TiAlN layer. The wear progress rate of the tool decreases as the TiBON film thickness increases. Specifically, the life of tools with a TiBON film is twice as long or longer that of tools with a TiAlN film when Inconel 718 is being cut. The mechanism behind the extended tool life is a combination of the effect of preventing adhesion by the formation of oxide material along with the lubrication afforded by the deposition of BN in the high temperature range.
Study on High-Efficiency Finish Turning of Carburized Hardened Steel with Driven Rotary Cutting
Authors: Kato Hideharu ,   Kanazawa Institute of Technology, 3-1 Yatsukaho, Hakusan, Ishikawa 924-0838, Japan, Shikimura Tatsuya , Morimoto Yoshitaka , Shintani Kazuhiro , Kubota Kazuyuki , Nakagaki Katsuhiro ,   Hitachi Tool Engineering Ltd., 13-2 Shinizumi, Narita, Chiba 286-0825, Japan,   Takamatsu Machinery Co., Ltd., 1-8 Asahigaoka, Hakusan, Ishikawa 924-8558, Japan
Published: April 2016

Recently, cutting has replaced grinding in the finish processing of hardened steel. However, tool damage is a major problem in high-efficiency operations that use high-speed cutting and high-feed rate conditions instead of the present cutting conditions. Therefore, the examination of a new cutting technique that can realize high-efficiency cutting is desired. In this study, the effects and efficiency of driven rotary cutting are investigated in the finish turning of carburized hardened steel. Based on the results, flaking occurs when single-point turning is used at the cutting edge at a short cutting length of 0.2 km. On the other hand, even if the cutting length amounts to 5.0 km, the tool wear width without flaking is small in the case of driven rotary cutting. Additionally, the tool wear is uniformly distributed along the circumference of the cutting edge. Furthermore, based on an examination of high-efficiency processing by increasing the feed rate, it is found that a feed rate of 0.3 mm/rev is the optimum condition from the viewpoint of wear resistance and surface roughness. Additionally, even if the cutting length amounts to 5.0 km for this condition, the flank wear is as narrow as 0.04 mm, and the tool wear progresses gradually.
A Basic Study on the Relations Between Machining Conditions and the Static and Dynamic Components of Forces in Drilling
Authors: Xu Jie ,   Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan, Yamada Keiji , Seikiya Katsuhiko , Tanaka Ryutaro , Yamane Yasuo
Published: April 2016

This paper discusses a method of converting thrust and torque detected during drilling, which transforms thrust and torque into equivalent thrust force and principal force. The static and dynamic components defined according to this method are used to evaluate instability. The effects of different conditions on the static and dynamic components are investigated through experiments.
Drilling of CFRP/Ti6Al4V Stack Board
Authors: Fujiwara Junsuke ,   Department of Mechanical Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan, Nagaura Ryuichi , Tashiro Tetsuya ,   Department of Mechanical Systems, Osaka Prefecture University College of Technology, 26-12 Saiwai-cho, Neyagawa, Osaka 572-8572, Japan
Published: April 2016

Drilling experiments with a CFRP/Ti6Al4V stack board were carried out using a TiAlN-coated cemented carbide drill, TiAlCr/TiSi-coated cemented carbide drill, and TiSiN-coated cemented carbide drill. Cutting experiments were carried out under a dry cutting process and water-mist-cooling process. Themain results obtained were as follows. The tool life of the TiAlCr/TiSi-coated cemented carbide drill was the longest among the three coated cemented carbide drills. The tool life under the water-mist-cooling process was longer than that under the dry process. Because the titanium alloy chips were much harder under the water-mist-cooling process, the cutting torque under this process became larger with an increase in tool flank wear compared to that under the dry process.
Special Issue on Precision Positioning Technology
Authors: Yoshimoto Shigeka , Tanaka Toshiharu
Published: April 2016

The 5th InternationalConference on Positioning Technology (ICPT2012) held at Garden Villa in Kaohsiung, Taiwan, on November 14-16, 2012, attracted over 100 participants, who engaged in intense, enthusiastic discussions on positioning technologies. Dr. Toshiharu Tanaka, who coedited this special IJAT issue, planned to feature ICPT2012 presentations and asked presenters to submit papers. 14 papers have been submitted and evaluated by two reviewers. Of these, 12 papers have been accepted for publication. Given the excellent quality of the papers in this special issue, readers are certain to find invaluable nuggets of knowledge in positioning technologies. I sincerely thank the authors for submitting their papers and would like to express my deep gratitude to the reviewers for their invaluable comments.