The authors constructed the load distribution theory that considers the deformation of the carriage and the rail by using FEM. As a result, the analytical accuracy of Linear Motion Guide has improved greatly. Next, the authors improved this theory, reduced an analytical cost, and constructed Linear Motion Ball Guide System load distribution theory that considers the deformation of the table and the base by using FEM. The authors experimented to verify this new theory. In this report, the authors report on the result of comparing the experimental and theoretical.

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Machine tool spindles are forced a preload in order to improve the stiffness. However, actual preload changes are not clear though the spindle might be damaged when preload becomes excessive by the rise in heat by the rotation. In this report, a trial that the states of the spindles under the rotation are clarified by measuring an axial natural frequency of the spindle that actually rotates. Two spindles with different kinds of preload methods, fixed position preload and fixed force preload, were examined.

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New life theory for rolling bearings is propounded by a linkage between the rating life data converted into the same size with bearing races in relation to the characteristic data of material carried out by alternating torsion probabilistic stress-life (P-S-N) test for hourglass shape specimens (Weibull slope ms_2=3/2, D_eo=φ8 mm) and the theoretically equivalent rating life data for bearing races (m= 10/9 for point contact bearings and m =21120 for line contact bearings). The 90% load rating formulas for races and a whole bearing are developed with a linkage factorβ, and then a newly introduced 100% load rating formulas are postulated with a linkage factor βby using the minimum life data for the life distribution data of ball bearings #6206. Consequently,β = 2A,β' = 2.16 and a reduction factor of rating loadλ=β'/β = 0.9 can be evaluated.

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This paper analyzes the natural vibration of a single carriage of linear roller guides. The carriage was excited by an impulse hammer through an added mass and its response was detected by an accelerometer. The acceleration was analyzed by an FFT analyzer. The linear roller guide has three rigid body modes. The motion directions of these modes are roll, pitch. and radial direction. The natural frequencies and compliances were measured changing the added mass. The mathematical model of carriage was proposed for identifying the natural frequencies, compliances and damping ratios. This mathematical model includes the roller model. The contact stiffness between roller and raceway is modeled as linear spring. Moreover, assuming the vibration damping is caused by interaction of roller and raceway, the damping force is modeled. This mathematical model can calculate the natural frequencies and compliances well. And the damping capacity of carriage is evaluated as damping ratios.

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Factory automation by the robot hand is expected to improve productivity and safety. In order to grasp the object there is a bias in the center of gravity, it is necessary to measure three axis load and torque. In this study, we aimed to develop a flexible contact sensor for four axis load measurement. The developed sensor is composed of elastic body and load measurement layer using pressure-sensitive conductive material. In this paper we describe relationship between voltage output and the deformation amount of elastic body when sensor is loaded.

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This paper describes an adaptive control method for a magnetic drive actuator that used for the laser cutting to realize high speed and high accuracy machining. Firstly, a zero bias current method and a nonlinear compensator are examined and used for the actuator. Secondly, an adaptive control method is presented. Finally, the coefficient of the gap-current-force is estimated and the effectiveness of the presented control method is verified by experiments. The experimental results show that the coefficient of the gap-current-force reduces exponentially depending on the increase in the length of the air gap- By using the adaptive control, the peak-to-peak vibration amplitude of the lens holder is reduced from l .95μm t0 1.55μm. Moreover, the magnetic drive actuator has a positioning resolution of 0.75μm, a bandwidth of 141Hz and a positioning stroke of ±0.5mm.

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Electrical discharge machining has the capability of machining all conductive materials regardless of hardness, and has the ability to deal with complex shapes. However, the speed and accuracy of conventional EDM are limited by probability and efficiency of the electrical discharges. This paper describes a tree degrees of freedom (3-DOF) controlled, wide-bandwidth, high-precision, long-stroke magnetic drive actuator. The actuator can be attached to conventional electrical discharge machines to realize a high-speed and high-accuracy EDM. The actuator primarily consists of thrust and radial magnetic bearings, thrust and radial air bearings and a magnetic coupling mechanism. By using the thrust and radial magnetic bearings, the translational motions of the spindle can be controlled. The magnetic drive actuator possesses a positioning resolution of the order of micrometer, a bandwidth greater than 100Hz and a positioning stroke of 2mm.

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Two types of guideways were developed as those for machine tools; dynamically pressurized guideway and partially floated gudeway. The first guideway utilized a newly developed analysis program, and has features that it is of split type and its slidway shape goes gradually narrow across the center width. It restrains the guideway from floating and tilting. It also restrains friction force generated. The second one is futured with our original mechanism which is an oil-lift style employing technologies of statically pressurized guideways. It leads to low-friction and high-accuracy feed.

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A high stiff rotary grinding machine for 450mm wafer has been designed and developed by the authors. The grinding machine is composed of a grinding-wheel spindle with a feeding function, water hydrostatic work table, and kinematic couplings which rigidly fix to the upper unit of the machine including the wheel spindle and the lower unit including the work table. The measured static stiffness of the work table was 1.61kN/μm when water-flow rate each bearing pad is at 10mL/min.

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In order to develop a water hydrostatic bearing for rotary table of 450mm wafer grinding machine, fluid analysis around the bearing pad was conducted numerically by using ANSYS FLUENT. As a result, the relationship between bearing clearance and sustaining force for each flow rate was obtained. From the relations, load capacity and static stiffness were estimated. Then, the estimated results were compared with the experimental.

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This paper describes improvement of injection molding characteristics using a sprue bush circulated with coolant channels. Since shortening of cooling time is necessary to shorten fomining cycle time, an injection molding tool was manufactured by diffusion bonding of laminated metal plates to obtain high temperature response due to circulated coolant. In the case that the molded part is thickest at the sprue runner, however, the minimum cooling time is determined by the cooling rate at the sprue runner. Hence, we produced a sprue bush circulated with coolant channels by the technique of difiusion bonding of laminated metal plates, and researched the effects on injection molding characteristics.

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Water driven stage, which is composed of water hydrostatic bearings and water hydraulic piston, was developed for the linear stage of ultra-precision machine tool. Constant feed motion of the stage is needed to produce fine finishing surfaces. To achieve constant feed motion, the design of speed control system is needed. Thus, a mathematical model of the stage was considered in the previous report. This report deals with an open-loop control of the water driven stage with a solenoid-type flow control valve. A mathematical model of the open-loop control system is derived with the use of experimental results. The results indicate that the feed motion less than 1mm/s is achieved by the control system. For instance, the speed of 1 mm/s was obtained by applying the input voltage of 6 V to the flow control valve. The derived model can be used to design feedback control system.

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Water driven stage was developed for use in the ultra-precision machine tools that is used for single-point diamond turning processes. A feature of the stage is that the size of the stage is small. Accordingly, the stage is advantageous for machining small precise parts in size. High bearing stiffness is needed for the performance of the ultra-precision machining. Even the size of machine tool is small, however, the bearing stiffness must be over acceptable level. A table of the stage is supported by water hydrostatic bearings. The stiflhess of the water hydrostatic bearings of the stage is thus considered via experiments and prediction using mathematical model. The experimental results show that the stiffness of the water hydrostatic bearing was approximately 34 N/μm if the supply water pressure is 0.4 MPa. Furthermore, it is indicated that the bearing stiffness can be 125 N/μm by the optimum design of the restrictor.

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For ultra-precision machine tools, hydrostatic bearings are the key components to determine the machining accuracy. This paper deals with a design method to determine optimum restrictor that maximizes the stiffness of water hydrostatic bearings. A short-pipe model of the restrictor is tested by comparison with the experimental results, showing good agreements with the prediction by the derived model. Introduced mathematical model is used to derive a useful equation representing the optimum aspect ratio of the short-pipe restrictor. It is noted that the equation is defined with newly defined non-dimensional parameters. Based on the derived equation, the paper also provides a useful graph in which the designer can easily find out the optimum aspect ratio of the restrictor for their hydrostatic bearings so that the bearing stiffness can be maximized.

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Demands for high precision and high efficiency of a machine tool have recently increased. In order to meet such demands, more efficient oscillating control and higher rotational speed of a spindle system are required. In this study, a new balancing method which does not cause an unstable oscillation and enables flexible to change of unbalance is proposed. Based on the proposed method, an auto balancer with the low melting temperature alloy is developed. Experiments are conducted and the performance of the proposed method is evaluated.

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One of the problems of the conventional method for identification of geometric deviations of five-axis machining center is that it takes a long time to setup. For example, in the method using the ball bar, it is necessary to carry out four kind of measurement in order to identify the eight geometric deviations. Therefore in this study, we propose a highly efficient method for identifying the geometric deviations. As as a result the validity of the measurement method proposed in this paper was shown with simulation. Moreover, the eleven geometric deviations including squareness errors could be identified in a single measurement process

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This paper proposes a method for the identification of all of the geometric deviations in five-axis machining centers by simultaneous multi-axis motion. In our previous study, ignoring the squareness deviations among translational axes, eight geometric deviations about rotational axes have been identified successfully. However, the machining centers have in general some squareness deviations. Thus, the influence of the squareness deviations on the circular trajectories under simultaneous three-axis motion was analyzed, and the squareness deviations among the translational axes were corrected. Using the proposed method, the eight geometric deviations were correctly identified.

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ISO standards related to accuracy test of 5-axis machining center is currently undergoing the final stages. In this research, real cutting is performed by accuracy inspection about truncated cone cutting by the 5-axis simultaneous control under proposal, and cutting conditions and an evaluation method are examined. In addition, we also consider motion accuracy inspection by using ball bar interpolation accuracy of the proposed tests, simulating the cutting of the above mentioned truncated cone.

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The purpose of this study is to clarify the relationship between the dynamic motion error of feed drive systems and the finished surface. In order to achieve this purpose, finished surface simulation of cone frustum which is used by evaluating machining accuracy of 5-axis controlled machine tool is proposed. In this study, motion trajectory of tool tip and tool orientation by considering dynamic characteristic are simulated by model of feed drive systems of 5-axis controlled machine tool. Then finished surface of cone frustum is simulated by using these results. In addition, in order to clarify the valid of simulation result and influence of motion error of axes on finished surface, cutting test is carried out. As the results, the influence of motion error of each axis on finished surface is discussed based on the results of cutting tests and simulations

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This paper presents the development concept and new technologies adopted to the vertical machining center "MP-46V" for high-precision parts and dies/molds machining. In this machine, the rotational speed of the spindle and acceleration of feed axes are increased for reducing the machining time. Moreover, in order to minimize "Junction steps" the new spindle with the rotary shaft cooling system and the advanced Thermo-Friendly Concept for the spindle, "TAS-S" are adopted. In addition we introduce sample cases of dies/molds machining with "MP-46V".

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The measurement and evaluation of motion accuracy of rotational tool axis is very important, since the accuracy effects directly on the machining accuracy and tool life. However, only the run-out measurement of the tool has been carried out on-machine during rotation, and the measurement of the motion behavior of the rotational tool axis has not been done yet. Therefore, we have already proposed the principle of the on-machine measurement of the axis motion of the rotating tool such as milling tool. This paper shows the result of making the prototype of the measurement device based on that principle.

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Thermal deformation in machine tools influences greatly on the machining accuracy. Therefore the importance of evaluation of the thermal deviation in machine tools becomes high. Besides, the demand of effective measurement and evaluation of the thermal deviation is becoming strong, since spending the time for the test of the thermal deformation influences directly on the production efficiency of machine tools. Therefore, in this paper, we devised the method which can evaluate independently the characteristics of thermal deviation caused by the single axis linear motion with the multiple linear motions of all axes. As a result, this method showed the much effectiveness in machining centers.

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Following to the previous paper reporting the motion control compensation for machine tool by 2 dimensional scale system, we hereby propose the motion control compensation for machine tool by a magnetic scale reading measurement direction and small displacement towards two orthogonal directions. We also report configuration of this magnetic scale, as well as results of its functional verifications.

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The purpose of this study is to develop a cutting force estimation method based on servo information in ball screw drive machine tool. In this method, the cutting force is estimated by frequency analysis of servo motor torque. A frequency component depends on the cutting force is extracted from the analyzed data, and the cutting force is estimated by inverse transformation from the frequency domain to time domain. The motor torque is strongly influenced by the friction force especially in case of the axis stopped. In the proposed method, the estimated cutting force is calibrated based on the identified friction force when the force is detected along the axis stopped. In order to confirm the effectiveness of the proposed method, actual cutting tests and simulations are carried out. As the results, it is confirmed that the proposed method can estimated cutting forces accurately in case of the cutting force becomes larger than the friction force

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Conventional estimation method of contact stiffness of joints has been limited to where the relationship between load and real contact area indicates linear characteristics. However if roughness and waviness of the surface become larger, this condition of the relationship shows non-linear characteristics and then it was revealed the conventional estimation method cannot be applied to. Therefore, in this paper, more generic estimation method of contact stffiiess of joints which can be applied to the joint interface with various surface roughness condition was considered. As a result, it was concluded that even if this relationship shows non-linear characteristics, the contact stiffness per real contact area can be estimated by proposed method with power approximation function.

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Damping capacity of the machine tool is determined by the internal friction of the structural material and the frictional damping of the joint. In particular, improving damping capacity of the joint is known to be highly effective on the improvement of dynamic characteristic of the structure. However, it is generally indicated that the existence of the joint decreases static stiffness of the structure. Therefore, in this study, the method for improving damping capacity of the joint in jointed structures without reduction of static stiffness is experimentally considered. As a result, interfering disk spring at the joint improves damping capacity in jointed structures without reduction of static stiffness.

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The bolted joint has been frequently used as a jointing method of structures, because it is easy to joint structural elements. In order to accurately grasp the static characteristic of these structures, the analysis considering the bolted joint is required. However, if FEM analysis of static characteristics of the bolted joint with high accuracy is necessary to cany out, the number of elements in the model for analysis increases dramatically. In this study, we propose the simplified model for analysis of the bolted j oint, which does not degrade the accuracy of analysis. As a result, we could the simplified model for the bolted joint.

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To analyze chatter vibration, dynamic stiffness of a rotating spindle in radial direction is important . In this paper, dynamic stiffness of a rotating spindle can be measured by using the magnet loader, which is a electromagnetic loading device.

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A rolling guideway has mechanical contact surfaces between rail and carriage on rolling elements, which causes friction. As the change of friction force affects the motion accuracy, knowledge of friction force is important. In this research, the friction force is analyzed by measurement of an experimental rolling guideway and simulation with locomotive multi-bristle model. The change of friction force with and without grease lubrication is simulated by using the numerical parameters identified by measurement. Comparing the results, an effect caused by grease lubrication on friction force is observed.

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This work aims to clarify that the effect of bending speed and repeated reverse crease on the bending characteristics of white-coated paperboard. In order to reveal the fundamental characteristics, the bending moment resistance is measured. A 232 g/m2 white-coated paperboard was scored by a round-edge blade and a grooved counter plate. The bending test of the scored specimens by the CST-J1 was carried out under the specified parameters for investigating the bending speed chosen as six kinds and the retained time duration of 0,10s at the tracking angle. Regarding the reverse crease, the relationship between the repeated number of bending and the gradient of bending moment was investigated.

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Since CFRP has light weight and strong characteristic compared with conventional structural materials. On another front, wood has been used in various forms such as furniture, house building. Instead of its light weight and low cost characteristics, compared with metal, strength is relatively low and often causes a brittle failure. So the application of wood to the structure for automobile, etc. is restrictive. In this study, the improvement of the mechanical properties of wood which is 10w strength and 10w toughness is explored. The composite plate of wood with thin CFRP layer is actually prepared. The result of having done bending testing is reported. By adding thin CFRP layer on 20mm wood plate, bending strength rises 130%. Furthermore by adding foamed material between thin CFRP layer and 20mm wood plate, absorbed energy rises 150%.

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On prior studies, it is showed that low frequency vibration drilling suppress the tool chip temperature rising and extend the tool life. Yet, particular mechanisms are not known. Researching the principle, allows to setup in an effective parameter for drilling difficult-to-cut materials at high efficiency. In this study, the cutting heats at each point of the tool were calculated. And by that, unsteady heat transfer analysis was simulated. Also, simulation results and experiment results was compared for checking the validness.

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The deterioration of machined surfaces by adhesion of work material onto the tool face was experimentally studied. The authors investigated the profile of machined surfaces in continuous and intermittent turning of Inconel 718 with K10 carbide tools. The cutting conditions having tendency to adhere metals were chosen by a method for evaluation of adhesion using dynamic components of cutting force. Profile of machined surface in continuous turning varied little. On the other hand, the profile in intermittent cutting frequently varied. This unstable adhesion probably results in the difficulty of milling of Inconel 718.

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Recently, the carbon fiber reinforced plastics (CFRP) are started using for many kinds of industrial products. In some cases, CFRP are pasted up on the metal in order to help cover the performance as the industrial products. In this study, the cutting mechanism has been studied when the multi-layered material made of CFRP and A5052 has been machined by abrasive water jet. The effects of the cutting conditions and the construction of the multi-layered material were investigated in the cutting processes. Also, the striations of the machined surface were evaluated with the surface roughness tester and the microscope. The surface characteristics of A5052/CFRP machined by abrasive water jet were found to be significantly different from CFRP/A5052.

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The demand of CFRP (Carbon Fiber Reinforced Plastics) has become heavy for its light weight and high strength. But it is a problem that the machining cost becomes high because the tool life is very short. An objective of this research is to clarify the tool wear mechanism. So the influence upon tool wear by the fiber orientation of CFRP was focused on. Then tool wear, cutting force and cutting temperature were measured during the milling of the unidirectional CFRP. As a result of the experiment, the relationship between tool wear and fiber orientation of CFRP was made clear.

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Because of high performance in mechanical properties and low density, carbon reinforced plastic (CFRP) is widely used as structural material for airplane, various kind of sports gear and premium automobile. Generally, production rate of CFRP structure is lower than conventional materials such as steel or aluminum alloy because the thermosetting process by using autoclave requires long cycle time. Recently, thermo-elastic resin is used as CFRP matrix to reduce the cycle time, press molding of CFRP within just one minute's time is achieved. The thermal properties of thermoelastic-resin is quite different from the thermosetting resin commonly used in CFRP, huge burr formation during trimming operation is often observed. In this study, the suitable machining parameters were proposed for milling through the machining experiments and thermal observation.

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CFRP (Carbon Fiber Reinforced Plastic) has higher specific strength, modulus of elasticity and so on. CFRP is, however, well known as difficult-to-cut material, which has very strong physical and mechanical characteristics. High-precision and high-efficiency cutting technique of CFRP is one of the most important cutting operations in industrial factory of aviation, automobile and so on. In this research the experiments are carried out making drilled holes on the laminated plates of CFRP with using two different shaped ball-nose end mills. It is found that the machining accuracy is affected by the tool shape of cutting edges on the cutting point.

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It is difficult to precisely machine soft objects such as rubber or sponge which have completely different characteristics compared to metals generally machined by machine tools. The study deals with the first trial of creating an artistic product shape of soft objects by employing an aqueous solution of sodium acetate to fix a workpiece and to improve the stiffness. As a result of conducted experiments, it is found that the usage of the aqueous solution of sodium acetate has the potential of realizing "Dexterous Machining" of soft objects.

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The workpiece setting is an important issue in process planning for 5-axis machine tool. However, in order to know the workpiece setting is proper or not, several NC programs for machining operation have to be prepared for trial-and-error examination to select the most suitable NC program by the trial cutting or the virtual machining simulation. In order to reduce the huge amount of time and effort for this trial-and-error determination method, the most suitable workpiece setting has to be determined first. In this study, the decision method is proposed to predict the machinable space using a virtual machine tool model, virtual cutting tool models, and the Form Shaping Function. In addition, the measure of accessibility of the cutting tool can be visualized. As the result, workpiece setting can be determined in the early stages of process planning.

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In order to achieve flexible and advanced machining, a system called Digital Copy Milling (DCM) was developed in our previous studies. Additionally, active tool motion control, in which Voxel property of removal volume Voxel model is referred, is integrated on the DCM. In this study, transition of tool posture is considered as a diffusion phenomenon, and formulated to determine a tool posture changed gradually from a tool posture at the finish surface for removing material. In the cutting experiment, tool postures for removing material are determined automatically by diffusion equation, and the ability to control tool posture independently against to the tool path generation is verified successfully.

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This paper describes a possibility for applying a rapid prototyping technique to informed consent. For this purpose, 41 system for generating human body parts from DICOM data (including image data of CT or MRI) to manufacture a real model with using a RP (Rapid prototyping) machine has been developed. As a case study, a lumbar spine is constructed as 3D model data format from DICOM data and then manufactured by RP machine, and a feasibility of the proposed system is demonstrated in this research.

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