A calculation model is proposed to examine generation mechanism of many lobes on inner-wall of airway in asthmatic patients and to clarify luminal occlusion of the airway inducing difficult breathing. The basement membrane in the airway wall is modeled as two-dimensional thin-walled shell having inertia force due to the mass, and smooth muscle contraction effect is replaced by uniform transmural pressure of the basement membrane. A dynamic explicit finite element method is used as a numerical simulation method. To check validity of the present model, simulation of asthma attack is performed. The number of lobes generated in the basement membrane is increased when the transmural pressure is applied in shorter time. When the remodeling of the basement membrane occurs characterized by thickening and hardening of it, it is demonstrated that the number of lobes is decreased and the occlusion of the airway lumen is progressed further. Comparison of results calculated by the present model with those measured for animal experiments of asthma will be possible.

抄録全体を表示

The vibration of suspensions of hard disk drives must be reduced if track density is to be increased. To reduce the vibration of the slider in the tracking direction caused by airflow, which is called windage, we used the FEM to analyze the vibration characteristics of suspensions. Deformations of load beams after the loading of disks are considered. Excitation force in the vertical direction is added to the suspensions as the substitute of fluid force. Our analysis showed that the vibration characteristics of suspensions change when the load beam profiles change, that viscoelastic dampers can reduce the windage sensitivity of the first torsion mode to Z-height, that the sensitivity of a suspension that has a large damper with stainless steel coverplate and from which part of the flange has been cut is only 1/20 that of the same suspension without dampers.

抄録全体を表示

This paper deals with a theoretical modeling and stability analysis of multiple flexible disks rotating in a confined fluid. In the stability analysis, the basic equations of the fluid flow around the rotating disks are based on Navier-Stokes equations and the structural vibration equations of the rotating multiple flexible disks are based on the Kirchhoff-Love's thin-plate model. These equations of the fluid-structure coupling motion are linearized around the equilibrium state. The variations of the modal frequencies and the modal damping ratios of the system are calculated as a function of the disk rotational speed. And the effect of the number of the disks on the critical speed is examined. As a result, the analytical results show a good agreement with the experimental results, and clarifies the effect of the number of the disks on the stability and the characteristics of the unstable vibration.

抄録全体を表示

Frequency responses of two- and three-dimensional liquid motions in a partially filled rectangular tank, subjected to a pitching excitation at a frequency in the neighborhood of the lowest resonant frequency, are investigated. The nonlinearity of the liquid surface oscillation and the nonlinear coupling between the dominant modes and other modes are considered in the response analysis of the sloshing motion. The equations governing the amplitude of those two types of liquid surface motions are derived and the stability analysis of each motion is conducted. An experiment was carried out using a model tank. Good agreement was found between the theoretical and experimental results. It is shown that the nonlinear analysis is important for estimating the sloshing.

抄録全体を表示

In a previous paper, the first author proposed an experimental identification technique for boundary conditions of a circular plate for the axisymmetrical case. In that paper, the boundary conditions were assumed to be linear. In this paper, an attempt is made to generalize the technique so that it can be applied to the case in which the boundary conditions are nonlinear. The main procedures of the proposed technique are (1) determining the displacement in an analytical form by combining experimental data with the theoretical solution, and (2) determining the boundary conditions by using the principle of harmonic balance. Numerical simulation is conducted. It is confirmed that (1) the proposed technique determines the boundary conditions when noises are small and that (2) use of data of strains in addition to those of displacements improves accuracy.

抄録全体を表示

In the research of structure damage detection, the method used computer simulation with finite element model (FEM) and LVQ neural network has been demonstrated its availability. But in practice, measurement points and measurement parameters optimization should be considered for updating the accuracy and efficiency of the detection. A method of measurement parameter selection by statistical analysis is presented in this paper, which has the ability to select the most efficient measurement parameters as the input vector to the neural network and minimize the numbers of the measurement parameters.

抄録全体を表示

The purpose of this work is to develop a linear damper in the wing of the aircraft. Then it requires the following: (1) The damping force have to be large for low frequency because the vibration frequency of the wing is small. (2) It works for small displacement, (3) Its size has to be small which can be stacked in the wing, and (4) Passive damper is desirable. This article presents a new type linear damper, which satisfies the conditions as just mentioned. The damper consists of a number of thin plates with slits. MR fluid is filled in the damper, so that magnetic fields freeze MR fluid. Resisting torque (friction torque) is generated when the plates slide due to the shear of slits of the plates. The damper works against the bending moment of the wing by responding its deflection. The damper is maintenance free, and it is one of passive dampers with a good durability.

抄録全体を表示

In order to investigate the dynamic characteristics of bolted joint part, we carry out the experiment and FEM dynamic simulation with contact for the cylinder connected with flange by 6 bolts. As the result, we confirmed that FEM dynamic simulation with contact coincide with experiment, and cleared that as for thick flange, the dynamic characteristics of bolted joint part is not influenced by contact pressure of flange surface, on the contrary as for thin flange, contact pressure of flange surface influences the dynamic stiffness of bolted joint. So, it is cleared that we can improve the dynamic characteristics of bolted joint part by about 100%, controlling the contact mode of thin flange easily.

抄録全体を表示

Sound-absorbing inner-roof which is made of PET (Poly Ethylene Terephthalate) fiber has been developed by the authors. Sound-absorbing inner-roof is polyester fiber board, so it is harmless and recycable. First of all, we explain tractor cabin structure and double roof ceiling. Secondly, we investigate the Sound-absorbing characteristics of the polyester fiber board with backward air layer, because the ceiling of tractor cabin consists of double roofs in which the air conditioning parts are installed and space is exists. As a result, the calculation of Sound-absorbing characteristics coincide with measurement result, and it becomes clear that the sound-absorbing characteristics of the polyester fiber board is better than that of polyurethane foam. Finally, we adapt the polyester fiber board to the inner-roof of the tractor cabin. Then we confirmed that the polyester fiber board reduces the sound level 2.4 dB, especially, 6 dB at 1/3 octave band of 500 Hz.

抄録全体を表示

An acoustic tube was developed and applied using the volume velocity measurement method for the prediction of constant exterior engine noise. Using accelerometers to measure engine surface vibration is a difficult task, especially for places like the exhaust manifold. The proposed method, an acoustic tube containing a microphone is set at a given distance from the engine and measurements are made in such a way that the whole engine surface is covered. Exterior engine noise at a certain distance from the vehicle was predicted by using the measured volume velocity values and propagation characteristics. The predicted results agreed well with previously experimented values.

抄録全体を表示

In this paper, a new type of isolation table using an X - Y table and spiral springs was developed. The damping of the isolation table is given by the friction force and the viscous damping of the X - Y table, and the stiffness is given by the spiral springs. The trial isolation table was made and its resisting force characteristics were measured. The seismic responses of the isolation table having a weight or a 3-story tower-like structure on board were also measured using an electrohydaraulic type shaking table. The experimental results are compared with the calculated results, and the effects of vibration suppression of the table and the overturn moment acting on the table are discussed.

抄録全体を表示

This paper presents a robust design method of a flexible structure reinforced by FRP sheets. A FRP sheet has a high ratio of strength to weight and is widely used as a stiffener of structure in various fields. Vibration characteristics of the structure reinforced by FRP sheets can be easily modified by changing design variables such as the relative volumes of fibers and matrix, the fiber angle and the number of layers. Therefore small variation of design variables gives rise to drastic change of the vibration characteristics. In this paper, the attention is focused on the variation of modulus of longitudinal elasticity of the structure reinforced by FRP sheets. We propose a constrained condition that can take into account the variation band of the elasticity of the structure and specify the total variation of natural frequencies of low order modes. For the purpose of maximization of natural frequencies, the design variables are determined by using optimization technique under this condition. The validity of the present method is verified by numerical examples and by comparison with results of experiments.

抄録全体を表示

This paper describes theoretical and experimental study of friction drive characteristics between a rubber-layered rigid roller and a mated rigid roller based on the Boundary-Element Method. First, under the assumption of plane-strain, we analytically derived Green's functions of a rubber roller with a rigid core based on cylindrical coordinates. Second, a contact problem of a rubber-layered rigid roller and a mated rigid roller under normal and tangential forces is numerically analyzed by Green's functions derived above. Normal and tangential contact pressures, strain of rubber, and contact region are repeatedly calculated so as to satisfy given normal and tangential forces. Tangential velocity ratio between two rollers is calculated as a function of tangential to normal force ratio for various rubber thickness values. Calculated results clearly indicate an influence of the thickness of rubber on the velocity ratio characteristics. Then, the friction characteristics of rubber-layered roller are measured experimentally. The numerical results are found in good agreement with the experimental ones.

抄録全体を表示

This paper describes the control and behavior of a simple robot, consisting of a pendulum and an inertia rotor, which can mimic gymnastic bar exercise. The rotor is rotated by a torque-limited DC servo motor fixed to the pendulum. The center of gravity of the rotor on the pendulum is invariable. The swinging motion of the robot is due to the reaction of acceleration torque of the inertia rotor. By means of energy control, the robot can be made to perform a swinging-up maneuver and a full swing around an iron bar. Moreover, the pendulum can be made to balance vertically above the bar means of optimal control after energy control as well as by means of trajectory control.

抄録全体を表示

We deal with a simultaneous optimal design of structural and control system of cantilevered pipes conveying fluid. We consider a combined pipe conveying fluid which is consisted of a beam (with variable shape) sandwiched by two pipes conveying fluid. The mathematical model of the combined pipe system is derived as a single pipe conveying fluid whose structural properties are variable. The width distribution of the beam and the location of the sensor and the actuator are structural design parameters. We employ the LQG control law with the input energy constraint as the active control method. The structural design parameters and the LQG controller are simultaneously adjusted so that the critical flow velocity of the controlled system ( closed-loop critical flow velocity) is maximized with an iterative numerical optimization technique. The simulation result shows the necessity of the simultaneous optimal design approach in designing the active control system of the cantilevered pipe conveying fluid. The experimental study is also conducted. The experimental result fairly agrees with the simulation result and emphasizes the proposed design methodology.

抄録全体を表示

This paper considers the active vibration control of a distributed-parameter planar structure using smart cluster sensors. Difficulty in controlling the distributed parameter structure lies in an infinite number of vibration modes it has. To cope with this problem, the previous paper presented a cluster filtering approach that enables one to categorize all the structural modes into a finite number of clusters, each cluster possessing same properties in common. It is the purpose of this paper to generalize a smart cluster sensor that can deal with a generic rectangular panel with symmetrical boundary conditions. First, a design procedure of generalized smart cluster sensors is presented, thereby allowing an arbitrary placement of the sensors on a targeted panel. Next, a novel smart cluster control is shown that is capable of measuring all the structural modes and of avoiding observation/control spillover problems. Furthermore, the smart sensor output is described explicitly using the Fresnel integrals. Finally, the experiment of smart cluster control is conducted, demonstrating the validity of smart cluster control.

抄録全体を表示

Satellite communications are utilized widely fields -navigations, broadcast and scientific. Recently mobile communications and satellite broadcast are developing remarkably. And the active antenna pointing sysem is required so that we may communicate with satellite in transportation, such as sail boat, truck and car. In this case, we can assume that the antenna base receives perturbation of a high frequency, and we must construct a compact antenna control system with high response. In this research, we use an existing antenna system consisting of a 2-axis gimbal structure driven by stepping motor and a 3-axis vibratory rate gyroscope to control the base attitude. The antenna system is used to track a Japanese broadcast satellite in geostationary orbit. We propose intellectual satellite position search system with feedback control using AGC level and feedforward control using gyro sensor to correct various errors. This papers discusses the 2-axis gimbal structure, sensor system, control algorithm, and experimental result.

抄録全体を表示

The car has various problems which is the traffic accident, congestion, pollution, and the resource consumption, etc. However, recently the realization of AHS (Automated Highway System) which is one of ITS (Intelligent Transport System) is enumerated as an effective solution of these problems. This paper describes the effectiveness of the discreat-time sliding mode control system in the simulation and the experiment. Two radio controlled cars of 1/10 scales on the market are used for the experiment device. The radio controlled car is autonomous because it is equipped with the microcomputer which printed out the program of control system, ultrasonic sensor for measuring the distance between cars, and the photo transistors for steering wheel control. It makes two radio controlled cars ran by steering control on the oval course. The distance between cars is observed by VSS observer. And this paper verifies it's effective.

抄録全体を表示

This paper considers the problem to design force controller for a one-link robot manipulator with contact motion to environments. Generally, the environmental characteristics that the manipulator is in contact with are not often known, and some of them have nonlinearity. Therefore we assume the environmental characteristic which is identified in real time as the spring element, and make the it scheduling variable. We propose a new type of sliding mode controller with gain scheduling type variable hyperplane. By using this controller, hyperplane can be changed for various environments and adapted to nonlinearity of the environmental characteristic.

抄録全体を表示

This paper shows an optimal placement of actuators/sensors for static shape control of truss structures with partial measurements. The location of the actuators/sensors is determined by the genetic algorithm in order to minimize the objective functions that are related to control effects for actuators and estimation errors for sensors, respectively. Unmeasured shape is estimated with a modal expansion method. An example of an antenna truss is discussed to assess the performance of the present static shape control. It is shown that the present placement method for actuators and sensors are effective for the control of truss structures.

抄録全体を表示

For autonomous mobile robots, sensors are very important to recognize an environment. In this paper, we pick up ultrasonic wave sensor, which today is the most common technique employed on indoor mobile robotic systems, and we propose a new technique to avoid crosstalk of sonar sensors. Even though many methods have been proposed to avoid crosstalk, it is very difficult to eliminate the influence of crosstalk perfectly. In this paper, supposing the continuity of the distance signal given by the sonar, we smooth the distance value. The estimator is based on the sliding mode system.

抄録全体を表示

In this paper, we present a method of position estimation for a mobile robot using a novel accelerometer. Compared to other methods involving landmarks utilization, odometry and GPS, an accelerometor-based method has the following advantages: (1) it is easy to install and (2) it is possible estimate position on uneven ground and indoors. However, because slight acceleration errors cause enormous distance errors, it is difficult to estimate the position by using an accelerometer. Therefore a servo-type accelerometer that has the highest accuracy among conventional accelerometers is used for the position estimation. But the sensor is expensive and is not good at estimating the position of an object that moves slowly like a robot. One of the reasons for the latter is that the data of the sensor is analog and the sensor needs AD converter. In this study we developed a new accelerometer with the aim of an accurate and inexpensive sensor, and proposed a method for using it in position estimation. The detecting module, an Inductcoder, provides digital data. The mobile module consists of a ball and two springs that causes no drift for the fluctuation of the temperature. The performance of this device was evaluated experimentally.

抄録全体を表示

This paper deals with an attitude and vibration control for free-flying space robot, which provides one main body, one 2-link arm and two flexible solar paddles. The robust cooperative controller is presented for suppressing both the attitude variation of the main body and the vibration of the flexible solar paddles which are caused by the reaction force due to the arm's motion. Actuators to be control cooperatively are composed of both thrusters and a reaction wheel. As a result, good performance is obtained from numerical simulation and experimental results.

抄録全体を表示

Growing complexity of artificial systems arises reliability and flexibility issues of large system design. Robots are not exception of this, and many attempts have been made to realize reliable and flexible robot systems. Distributed modular composition of robot is one of the most effective approaches to attain such abilities and has a potential to adapt to its surroundings by changing its configuration autonomously according to information of surroundings. In this paper, we propose a novel three-dimensional self-reconfigurable robotic module. Each module has a very simple structure that consists of two semi-cylindrical parts connected by a link. The robotic module system is capable of not only building static structure but also generating dynamic robotic motion. We present details of the mechanical/electrical design of the developed module and its control system architecture. Experiments using ten modules with centralized control demonstrate robotic configuration change, crawling locomotion and three types of quadruped locomotion.

抄録全体を表示

The rings event is one of men's apparatus gymnastics, and has free-floating characteristics at the gripping point that do not exist in the other gymnastic events. In this paper, we propose a rings gymnastic robot intended to apply it to the coaching. Joint torque in exercises is informative for the coaching and gymnasts can easily obtain the knowledge to realize exercises if a control law of the torque is represented as "if-then" rules. Therefore, we adopt fuzzy control as a control strategy for the rings gymnastic robot. The purpose of this paper is to acquire suitable fuzzy rules for realizing a series of exercises, which is a handstand from backward giant circle. Simulation results show the effectiveness of the fuzzy rules and a guideline for the coaching can be read from the fuzzy rules.

抄録全体を表示

The authors developed an anthropomorphic talking robot WT-1 (Waseda Talker-No. 1). It simulates human vocal movement by using artificial vocal organs (lungs, vocal cords) and articulators (lips, teeth, tongue, nasal cavity, soft palate). We experimented it on vowels. Although WT-1's voice wasn't equal to human, it could utter all Japanese vowels (/a/, /i/, /u/, /e/, /o/).

抄録全体を表示

This article describes a robotic system that assists a human to carry a long/big object in 3-D space. We assume that the operator and the robot grasp each end of the object and carry it cooperatively. In this task, it is difficult for the human to give a translational force at the robot hand by a torque control. Therefore, we propose to assign a virtual nonholonomic constraint to the robot hand. In this method, the robot behaves like a unicycle and we only use translational force to manipulate it. The controllability is assured based on nonholonomy and the operator can transport the object to the desired position and posture in 3-D space by similar skill using wheelbarrow. The effectiveness of our method is experimentally verified.

抄録全体を表示

Grip force and contact condition including stick/slip are measured to investigate the mechanism of dynamical transmission of contact information to tactile afferents in precision grip of human. A system for measuring normal/tangential forces and stick/slip condition between the human finger and grasping object is made. As a result of measurement, it is found that the increase ratio of the grip force and the change in stick area are mutually related. Contact condition is also calculated using a FE (finite element) analysis. It is found that the stick/slip condition shows the similar phenomena as experiment. Change in SED (strain energy density) at the Meissner's corpuscles' location shows local maximum at the slip area. The relationship among the SED at the location of Meissner's corpuscles, the deformation of the finger and the stick/slip condition in precision grip is shown. In other word, a model for transmitting the dynamic information from the contact condition to tactile afferent responses during precision girp is constructed.

抄録全体を表示

Soft-body creatures including earthworm, caterpillar and inchworm have their own locomotion pattern. They have common features as simple continuous segmental structure of their body and locomotion pattern in cooperation with partial motion of their body propagating waves. In this research, the influence of the structural feature of the soft-body creatures and the environmental conditions on its locomotion pattern are analyzed using genetic argorithms. As a result of the analysis, it is proved that the antagonistic muscle system of the soft-body creatures that consists of hydraulic framework urges its emergent acquisition of locomotion pattern by propagating the waves. It is also proved that the strength of materials of their body, power mass ratio and environmental conditions affect the difference in their locomotion pattern. The acquired locomotion patterns correspond well with these of the earthworm, caterpillar and inchworm.

抄録全体を表示

Design parameters such as gear dimensions, material, and support stiffness of gears are usually fixed before tooth flank form design. They have big influences on the characteristics of gear performance. When those parameters are fixed inappropriately, it is therefore difficult to satisfy requirements for vibration and load carrying capacity, even if optimum tooth flank form is given. In this report, the mutual influence of those parameters on the gear performance is investigated by using the proposed optimizing design method of tooth flank form, which minimizes vibrational excitation of gears while satisfying requirements for load carrying capacity. Higher geometrical total contact ratio ε_γ mostly results in lower vibrational characteristics of gears with the optimized tooth flank form, but that is not always true, if the requirements for load carrying capacity are severe. Increase in material allowance limits in load carrying capacity can lower the vibrational excitation of gears with optimum tooth flank form. The vibrational excitation at gear mesh cannot be kept low, if the support stiffness against alignment error of gears is not enough. On the other hand, the decrease of support stiffness of gears reduces the magnitude of excitation acting on gear box due to gear vibration. The favorable combination of the support stiffness in parallel shift and that in axes inclination is clarified, which makes vibrational excitation acting on gear box minimum.

抄録全体を表示

We tested poly butylene telephthalate (PBT) as a gear material in our previous study and found that it had larger fatigue strength and lower coefficient of friction than those of polyacetal used as a gear material currently. In the present study, since plastic gears that can transmit high power have been strongly demanded by the industrial world, we reinforced PBT by compounding grass fibers for higher power transmission than normal PBT and conducted operation tests on gears made of reinforced PBT. Wear behavior was particularly investigated under a relatively larger torque since plastic gears filled with grass fibers were expected to be worn significantly due to a fall of grass fibers from the mother material. Availability of PBT filled with grass fibers for a gear material was discussed by comparing basic operational characteristics with those of normal PBT gears.

抄録全体を表示

The tooth surface strength and wear of case hardened spur gears were studied in order to clarify them from the view point of tooth forms and pitch line velocities and also to obtain higher tooth surface strength than ever found. The test results showed that the face width influences a little on the tooth surface strength in the case of the face width being small. The cutter pressure angle and the profile shift do not influence on the tooth surface strength shown with Hertzian pressure, but these factors affect the power transmitting capacities very much. The tooth surface strength of case hardened in a vacuum gears and that of MoS₂ coated gears are about 15% and 30% higher than that of usual case hardened gears respectively.

抄録全体を表示

A rotor housing of a Wankel internal combustion engine has a peri-trochoidal form that is machined by the internal grinder that is operated by a form generating mechanism. The elastic deformation arises in the machine elements by inertia forces, torques and grinding force that are caused in the processing motion. And positional errors arise between a workpiece and grinding wheel according to the dimensional errors of machine elements and assembling structure. The ground formative accuracy is affected considerably by these factors. To grind the trochoidal form more precisely and efficiently, the authors have investigated the motion analysis about the mechanism. In this paper analytical results have been obtained about inertia forces and torques acting on the mechanism to estimate the elastic deformation. The calculated results are compared with the experimental ones. Good agreement was found between them. Some results are presented in the form of graghs and tables.

抄録全体を表示

The new method of reducing the noise of the rolling guide was studied. In the experiments, the overall sound pressure levels of rolling guides with steel balls or Si₃N₄ balls were measured, and the frequency analyses of the sound were carried out. Moreover, based on the assumption that the main cause of the occurrence of the noise may be the collision between the ball and the bearing block, the overall sound pressure levels of the rolling guides were analyzed combining the Hertzian theory and the results of previous studies on the collision sound. From the results of experiments and analyses, the conclusions were obtained as follows: (1) The overall sound pressure level of the standard rolling guide with steel balls can be reduced by about 4.5 dB by using Si₃N₄ balls having the same diameter. (2) The overall sound pressure levels of rolling guides with steel balls or Si₃N₄ balls were both increased about 9.8 dB as the linear velocity increased an octave. (3) Based on the assumption that the main cause of the occurrence of the noise emitted from rolling guide may be the collision between the ball and the bearing block, we perform two analyses: First, the increasing rate of the overall sound pressure level with respect to the linear velocity. Second, the difference of the overall sound pressure level of the rolling guide with steel balls and that of the rolling guide with Si₃N₄ balls. These analytical results match the experimental results well.

抄録全体を表示

A novel method for identifying the adhesion force and the dynamic elongation of molecularly thin lubricant coated over DLC surface was developed while an SPM tip retracting from contact position by using transient response of the SPM cantilever arising after separation. The accuracy of measurement of the cantilever displacement was considerably improved by mounting a silicon tip with optically reflecting surface on the cantilever to produce high quality image of the interference fringe pattern formed by Michelson interferometry. To describe experimental transient response, a model for separation process was introduced wherein the surface force decreases from an initial value (contact force) to zero in proportion to the tip travel accompanying elongation of the lubricant. Calculated vibration waveforms using this model were found to be in good agreement with observed waveforms. This hinted that PFPE thin film could stretch as much as a hundred times of lubricant thickness.

抄録全体を表示

Circularity tests method using laser displacement interferometer has been developed. The new measuring method features a much longer range of motion than ordinal circular tests method such as DBB method, with relative displacements measured by laser interferometer. Therefore minimum and maximum radius of a circular test path is under less restriction than a ball link system. Moreover, the measuring system can also be applied for evaluation of positioning accuracy in X or Y axis, and in XY plane. The proposed device consists of a laser interferometer whose interferometer head and retroreflector holder are connected with stainless steel rod. The stainless steel rod has a synthetic resin linear bearing, thus retroreflector holder is movable against interferometer and both optical components are always facing. The laser interferometer measures distance change between interferometer and retroreflector. At first, the measuring accuracy of the apparatus was measured, and the results were compared with capacitive sensor. Then, the apparatus was applied for circularity tests and positioning error measurements for a vertical machining center. The results obtained show the validity of the apparatus.

抄録全体を表示

Recently, super-finishing stones with super-abrasive grain widely would be used. So this paper describes abrasive grain falling Mechanism of the super-finishing CBN stones. The relationship between cutting force and abrasive grain falling under super-finishing processing was investigated. Considering crossing angle in the crossing cutting, the force which charged on an abrasive grain was investigated by the crossing model test. Then, by the phase difference considering the stone width, the relationship between abrasive grain loci and abrasive grain falling of the stone edge was examined. As a result, abrasive grain loci by the stone edge affect the grain falling and it is possible to be prevented the grain falling by average of crossing angle and contact area value on main force direction.

抄録全体を表示

A new ultra-fine piercing which had been proposed, have been conducted successfully, but has a few troublesome points. A die material is mild steel, and than a coupling of a die and a pierced material is that of metals. Therefore, pierced scrap accumulated in a die hole and stops a punch advancement. If the pierced material rises up unevenly from the die, a horizontal force acts on the punch and the punch defects, advances deviately and shaves the surface of the die hole. These were conquered by means of setting a vacuum chamber under the die. A scrap is sucked away from a die hole at each stroke and a foil of pierced material is pulled down through two holes remoted by 1 mm from the die hole. Thus a high precision and continuous process of the ultra-fine piercing is carried out.

抄録全体を表示

Machining system using miniature robot arm is proposed to apply for microfactory. Feasibility study about stiffness specifications are carried out, and target specification of robot arm elements are indicated based on leading-design-oriented approach. Cutting load of micro end milling is measured by high response/high resolution sensing system. The cutting load conducts a required stiffness of miniature robot arm. Optimum design problem is solved to get required and sufficient condition of sub-module specifications of the robot, which must be achieved to realize the proposing machining system. Results show that the specific load is about 1300 mN for cutting stainless steel, and tough requirement appears on bearing stiffness. High stiffness bearing system made of tungsten carbide is numerically evaluated and shown to achieve sufficient stiffness. Proposed system will achieve less than 4 μm deflection through stainless steel machining.

抄録全体を表示

It is very important to standardize mechanical parts as productivity increases. But, this is a very difficult subject, because there are a lot of kinds of different mechanical parts, and the mechanical parts are very complicated. Therefore, we have developed a support system, which standardizes the mechanical parts. The mechanical parts can divide into several components, and it is relatively easy to standardize these components. We built an individual standardization data base for each component, and link these data bases into a system. The system used a macro function, which records a series of operations of three-dimensional CAD system. This paper describes the methods for standardizing the mechanical parts by the macro function, with an emphasis on the method for building the standardization data base automatically, the method for generating a frame of input and output formats, and so on.

抄録全体を表示

The present paper aims to describe newly devised fold patterns to form foldable conical or truncated conical shells consisting of equiangular spirals and zigzag shaped spirals. Firstly, fundamental fold patterns are designed by combining two groups of equiangular spirals which cross in the same or opposite direction. The fold patterns consist of triangular elements. Based on these patterns, different types of patterns consisting of trapezoid elements are devised by using zigzag shaping equiangular spirals. Devised foldable models have been manufactured, and their foldabilities have been proved.

抄録全体を表示

The purpose of this paper is to present foldable tubes or conical shells with such non-circular cross-sections as rectangular ones. The developments of these structures consist of the combinations of two or more kinds of differently shaped structual elements, which form spiral configurations. Several kinds of such foldable tubes as well as conical shells are newly developed. Origami samples of foldable tubes and conical shells have been manufactured and their foldabilities have been checked. It has been assured that all samples are perfectly folded in axial direction.

抄録全体を表示

To improve manufacturing accuracy in stereo-lithography modeling, it is important to quantify the influence of laser power, laser beam diameter, scanning speed and the properties of photo-curing resin on the cured form of the resin, or cured resin thickness and width. Thirteen types of photo-curing resin prepared by changing the quantity of the initiator added to the resin were tested to examine the effect of resin properties, estimating the dimension of cured resin. It concluded as follows. (1) The phase change limit energy density and attenuation coefficient of the resin can be approximately expressed as a function of the quantity of initiator added. (2) The estimated values for thickness and width of cured resin, using approximated phase change limit energy density and attenuation coefficient of the resin, are well coincident with the measured values, implying thickness and width of cured resin can be estimated within practically allowable error. (3) Thus, once the quantity of the initiator added to the resin and the maximum energy density of the laser beam are given, the thickness and width of the cured resin are determinable.

抄録全体を表示