This paper presents experiments on the self-excited vibration of an elastic plate supported by air pressure. In this study, the vibration characteristics and the unstable conditions of the self-excited vibration are examined through experiments. The unstable conditions considering the influence of bending rigidity of the plate is clarified. The unsteady fluid force acting on the plate (bottom surface) is investigated by measuring the unsteady pressure. The local work done by the unsteady fluid force is also clarified. Lastly, the unstable mechanism of the self-excited vibration is discussed based on the experimental results.

This paper presents experiments on the self-exited vibration of a plate on air flow and an elastic support structure. In this study, the vibration characteristics and the unstable conditions considering the influence of support stiffness of the support structure of the self-excited vibration are examined through experiments. The unsteady fluid force acting on the plate and elastic support structure is examined by measuring unsteady pressure, and the local work done by the unsteady fluid force is clarified. Lastly, unstable mechanism of self-excited vibration is discussed based on the experimental results.

A plain plate is often used in structures such as the transportation equipment and home electric appliances. We face challenges of the cost reduction and weight saving in design of product. In this case, it is ideal to achieve them using cheap steel economically. In this study, we focused on the plate given in concavo-convex processing and curved surface processing and it is an object to clarify the difference in vibration characteristics between a plain plate and curved plain plate with rib. We analyzed rib curved plain plate model by means of FEM. We created an experimental model and conducted the experimental modal analysis then we compared the experimental value with the analytical value. In the result, we confirmed the validity of analysis model in out-of-plane vibration. Furthermore we compared the eigenvalue in plain plate and rib curved plate. In the result, we found the eigenvalue rise than the plain plate by using the rib curved plate.

We performed static and dynamic experiment and their analysis for the laminated cantilever beam which consists of 2 or 4 layered beams in order to find frictional influence on their properties. On static experiment and analysis we found that frictional force between layered beams influences on the stiffness. Loading the laminated cantilever beam decreases its stiffness. Increasing clamping force, changing point of stiffness moves toward the hard stiffness. On dynamic experiment and analysis, we found that frictional force influences on vibration properties. Making impact force strong, peaks of compliance and their frequencies decrease. 4 layered beams produce greater change than 2 layered beams.

A large shock occurs when launching the rocket. This shock depends on a combustion vibration. It causes serious damages to electronic equipments mounted with a satellite. Since the pay load of the rocket is limited, the satellite be required to reduce the weight. On the other hand, the weight reduction causes the stiffness reduction. Therefore, the resonance avoidance design is an important issue more than ever.
In this study, in order to reduce the weight of the small satellite, we verify the optimum vibration design of the structure panel using the FEM.

Measuring or calculating structural intensity (SI) affords us to understand the propagation paths of vibration and the amount of the transmitted power. In this paper, a new SI measurement system is developed. This system simultaneously uses many of MEMS sensors to save time. The requirement for this development is firstly summarized. An example of the system developed is presented. Secondly the characteristics of the MEMS accelerometers were tested from the view points with mismatch among the MEMS sensors each other. Also the frequency response characteristics of the MEMS sensors were tested by comparison with the results of the ordinary accelerometers. As a results, the accuracy of the MEMS sensors are not so high but are applicable practical uses by correcting signals. Finally it is demonstrated that the SI measurements on the beam and the plate are correct by comparison with the results by the ordinary SI measurement methods.

Railway vehicles are equipped with many kinds of machines such as traction diesel engines and their failures sometimes lead to service disruptions and accidents. A vibration monitoring system is expected to prevent their failures by detecting their abnormalities at an early stage. In order to make an effectual action after abnormal vibration detection, it is necessary to make a root cause diagnosis. To address this issue, a simple diagnosis method is proposed in this paper. In the method, a measured vibration octave spectrum is divided into three frequency bands and abnormality detections are conducted for each spectrum to narrow down the root cause of the vibration. The effectiveness of the method is verified using vibration data acquired on simulated abnormality tests of traction diesel engines.

The damage identification analysis based on filtering theory has a potentially effectiveness as a global monitoring both for identifying the damage locations and for estimating the extent of damage. In the computation process, the natural frequencies are utilized as observation data, and then the inverse analysis are performed recurrently to obtain the estimate values of system parameters. However, it is difficult to experimentally measure a large number of natural frequencies accurately. The purpose of this study is to develop a ranking approach to estimating structural damages. In this method, it requires only a few lower natural frequencies which can be measured experimentally. Although the location and extent of damages cannot be determined, the damage potential rankings are obtained as minimum required information to detect damage locations. In this paper, we conducted a damage experiment on straight piping and examined the influence of the bending moment acting on the damaged area on the accuracy of calculating the magnitude.

This paper presents a study on a rattle noise in BSR by comparison between experimental results and numerical analysis results as to a vibrational model by FEM. Simulating a rattle noise, the vibrational model is constructed with a contact state by putting two pieces of strip-formed sheets made of the plastic on top of one another. As an input waveform, random vibration and sweep vibration are used, displacement excitation method is applied on a node which is pinned support. As a result, the influence of contact could be confirmed from the time history response analysis result by FEM with contact and without contact. Also, the effectiveness of the vibrational model with the influence of rattle noise is examined through calculations employing a FEM model with contact and without contact in the power spectral results of the analytical and the experimental results, it is shown that the analytical and the experimental results are qualitatively similar.

An improved version of the elliptic averaging method is proposed in order to obtain a highly accurate periodic solution for a nonlinear systems based on Duffing oscillator having multi-degree-of-freedom. The sum of the elliptic Jacobian cosine (cn) and sine (sn) function is incorporated as the generating solution of averaging method. The stability of the approximate solution obtained by the proposed method is discussed by the characteristic multiplier based on Floquet's theorem. The results for typical nonlinear oscillators with two-degree-of-freedom system are shown. The efficiency of the proposed method is illustrated by comparing its results with the very accurate numerical solutions obtained by the shooting method. It is confirmed that the proposed method provides an accurate solution and stability analysis results, and it's effective to analyze nonlinear oscillator with multi-degree-of-freedom system.

In the construction site, an electric hammer, a type of hand held vibrating tool, is used to crush concrete, asphalt and so on. The frequent user of this tool is at high risk for developing the hand-arm vibration syndrome because of excessive exposure to hand-arm vibrations. In order to prevent the disease, it is required to keep the vibration of the tool's gripes as low as possible. The purpose of the present study is the development of a very low-vibrational electric hammer using self-synchronization phenomena in order to address the problem of the hand-arm vibration syndrome. In previous research, we developed a prototype with synchronous vibration generating mechanism for electric hammer, and performed performance evaluation by sand compaction test. As a result, we succeeded in generating a motion state for the purpose of simultaneously achieving excitation of the striking part and vibration suppression of the holding part. However, there was a problem such as rolling vibration being generated in the entire device. Therefore, in this research, in order to prevent the occurrence of roll vibration, we improved the prototype. Then, the influence of the pressing force and the initial crank angle on the daily vibration exposure amount and impact force was investigated.

In the case of fly fishing, the cast becomes the unique method using the weight of the line to throw the fly. It becomes important how the behavior of the line turns out in the case of casting. Because the fly line is a flexible string-formed structure, the behavior becomes complicated, and grasp or the modeling of the phenomenon are difficult. In this study, it is intended to clarify line behavior in the casting. The casting model was constructed an arm, a rod, a line divided into plural rigid elements by being connected in a rotary spring and a rotary damping element. The time history behavior is calculated by transforming a motion equation derived from a model, and doing numerical value integral calculus. The input wave was used the angular velocity of the arm obtained from the experiment. The line shape in the experiment was acquired by filming a line flying from the upper side. The line length is 7m. In a state holding a line in the rear, I cast the line only once forward. In the case of an expert, the loop shape of the analysis resembles that of the experiment, but the behavior of the rod was different. In the case of a beginner, the loop of the analysis result was closed, and it was different from that of experiment, but the shape when a loop opened was similar.

This study concerns a relation between four-legged animal’s switching gait patterns and natural vibrations of their musculoskeletal system. Four-legged animals are walking by switching gait patterns depending on speed of locomotion to minimize energy consumption. This is similar to switching natural vibration modes depending on a frequency in multi-degree-of-freedom vibration system. It is assumed to have a relation between natural vibration of the musculoskeletal system and the switching gait patterns. Therefore a passive walking mechanism, which walks using a natural vibration, is suited to examine the relation. In this paper, it is showed what elements are needed for switching gait patterns corresponding on road speed by passive mechanism. The leg of this passive mechanism has three joints and elbow is angle limited and forward deviation of neutral axis. The shoulder and waist which dose a spring support position inward can separate natural frequency of reverse phase mode and in phase mode. This passive mechanism can form three gait patterns walk, trot and gallop at appropriate road speed only contact road surface. But this passive mechanism cannot walk at the road speed between the speed exiting trot and the speed exiting gallop. It is considered that this problem can be solved by closing the natural frequency of shoulder and leg.

This study describes promotion action when the promotion mechanism using vibration is driven by self-excited vibration using the local feedback control. In this paper, the locomotion device consist of some carts with the friction mechanism which connected in series by springs is used. A bigger frictional force is generated at the time of backward traveling than at the time of forward traveling by this friction mechanism. The promotion mechanism using vibration promote by frictional force difference. The driving system by self-excited vibration using local feedback control is used. It is compared the promotional action of the device driving by self-excited vibration using local feedback control and driving by forced excitation. The device is promoted with high efficiency by using resonance when driving by forced excitation. The device driven by self-excited vibration is promoted with the same action as driving by forced excitation. The promotion mechanism using vibration promotes using resonance with driving by self-excited vibration using local feedback control.

Reciprocating compressors are parts of the most critical systems in many production facilities, and the long-term continuous operation must be required. However, their occurring troubles during operation are not simple but such various phenomena as degradation, wear, etc., are complicatedly intertwined. We focused on vibration characteristics of reciprocating compressors, which could be dominant in the dynamics responses in operation, and constructed the mathematical model to calculate the natural frequencies and modes for crank angles and proposed a method to estimate the degree and the suspicious portion of failure by difference of temporal parameter values, which are identified using measuring data and the mathematical model. In this paper, we apply the proposed method to the field data, where the wear of the connecting part might occur, and examine whether the abnormality detection could be evaluated. For this result, we could show the possibility of monitoring technique observing deterioration with the temporal model parameters determined by measuring data during operation

At stator coil end in turbine generator, there is bracket which holds the coil end structure by frictional force. Due to the frictional force, the load-displacement characteristic at the bracket has nonlinearity. To improve the accuracy of the modal analysis under operating condition, nonlinearity of load-displacement characteristics of the bracket should be evaluated, and equivalent spring constant of the bracket considering nonlinearity should be used for the modal analysis to consider the operating condition. In this report, load-displacement characteristic of the bracket was measured by tensile test, and equivalent spring constant of the bracket was evaluated. After that, natural frequency of the stator coil end considering operating condition was calculated using finite element method. In the result, the accuracy of calculated natural frequency related to electromagnetic vibration at stator coil end is improved by the consideration of load-displacement characteristic of the bracket.

The self-standing support method using the theory of the center of percussion is newly proposed in order to achieve the vibration reduction of a reciprocating compressor for refrigerators. In a typical compressor, the drive unit corresponding to the compressor body is flexibly supported inside the shell by four coil springs. Because the natural frequencies of the drive unit are relatively-low, the increase in vibration is inevitable while driving the compressor in a low rotation region. In contrast, in the proposed method, the drive unit of which the spherical element is attached on the bottom is placed directly on the shell. The self-standing state can be stably-maintained by the effect of the tangential component of the gravity. This restoring force is smaller than that of the coil springs, so the natural frequencies of the drive unit become lower compared with spring supports. In addition, the drive unit is optimally designed so that the contact point between the drive unit and the shell coincides with the center of rotation. It is possible to suppress the vibration transmission from the drive unit to the shell. In this study, the fundamental model whit an unbalance motor was developed in order to investigate the effective of the proposed method. The results of the numerical analyses and experiments confirm that the present method is very effective to suppress the vibration of the compressor.

This paper proposes a control allocation method for the motion control in which the number of manipulated variables is one more than control degree of freedom. Proposed method is formulated as an optimization problem including some of Quadratic Programming sub-problems (QPs), and can calculate optimal allocation in real-time. Furthermore, the real-time performance is improved by the Parallel Quadratic Programming (PQP) method. The effect of the proposed method is verified by numerical simulations in terms of control response and calculation time.

Zero-power controlled active magnetic bearing has been proposed in order to energy saving. The magnetic bearing consists of electromagnets with permanent magnet. The electromagnets are mounted on a frame suspended by springs. Using simple zero-power control for levitation, stationary current becomes zero even though a force acts on the rotor. While the rotor moves relative to the frame in the opposite direction to the force, the frame moves same direction as the force. Therefore, the absolute rotor position is maintained with low energy. However, the absolute position and the current fluctuate due to unbalance force at low speed rotation. While another control method has been proposed to regulate the fluctuation, the regulation effect is insufficient at high speed rotation. In this report, the switching method of control system depending on the rotational speed is proposed to obtain high performance at both low and high speed rotation.

Parallel magnetic suspension that controls multiple floators or multi-degree-of-freedom motions with a single power amplifier has already been realized. This study focuses on zero-power control in a two-degree-of-freedom parallel magnetic suspension system. The zero-power control is achieved by feeding back the integral of the control current. The characteristics of the zero-power control system are studied from an aspect of response to a stepwise disturbance. When the disturbance acts on one of the suspended points, a steady displacement appears only in the corresponding suspended point. To confirm this prediction, step responses are measured in the experimental apparatus.

This paper presents a controller design approach to suppress the effect of overturning moment in two-dimensional shaking table systems. In the system, overturning moment of specimen generally deteriorates the motion performance of the table, resulting in the lower reproducibility for the desired earthquake acceleration. In this paper, therefore, disturbance observer and acceleration feedback are applied to improve the disturbance suppression capability. The acceleration feedback compensator is designed to attenuate the resonant gain peak. The disturbance observer is designed to estimate and cancel the disturbance caused by overturning moment, where the bandwidth of observer can be expanded by including the acceleration feedback loop. The proposed approach has been verified by experiments using a laboratory two-dimensional shaking table system.

Torque-unit Manipulator (TUM) is a design concept of space manipulator. A device which is called ‘‘torque unit’’ is equipped on each link of a kinematic chain whose joints are free. The ‘‘torque unit’’ can be made easily of a rotary actuator and a disc. TUM is a kind of nonholonomic system and the angular velocity of each disc at each time depends on the trajectories of the links. Controllability has been considered to control the position of each link to desired position and the angular velocity of each disc to desired constant value, by planning the trajectories of the links for 2-dimensional N d.o.f. TUM. It consequently has been shown that it is impossible to control the angular velocity of each disc to desired constant value since TUM has a first integral. However the first integral allows us to control the angular velocities of the all discs to a constant value of zero. Then, a control strategy is considered and described based on the results of the consideration. The control strategy consists of two phases: 1) controlling the positions of the links to desired positions, 2) controlling the residual angular velocities of the discs to zero by planning trajectory of the links. This paper presents the conditions of the trajectory in phase 2) and simulation results of the control strategy described above.

This study aims to characterize the function of the practical inerters. Inerter is effective component for mechanical vibration system to control vibration frequency characteristics. Although most of the previous studies about inerter are examined with ideal inerter which ignore mass and inertia of the devices themselves. We formulate two types of practical inerters: torsional inerter including planetary gear unit and linear inerter using lack and pinion gear mechanism. Rearranging formulas from the viewpoint of the difference of the ideal inerter, it is confirmed that function of each practical inerter can be represented as the combination of three functions: “moment of inertia re-distribuion” and “direct connected inertia,” in addition to “ideal inerter” which is same as the function of ideal inerter. As the concluding remarks, similarity of function is confirmed between torsional and linear types of practical inerters.

The purpose of this study is to identify vibration properties of a digital printing machine. The digital printing machine is composed of several units, e.g. Laser Unit (LU), Photoconductor Unit (PC), Process Frame (PF), 1^st Transfer Belt Unit (TB), etc. They are mounted on a frame structure and the vibration properties are softly coupled. In a previous study, vibration properties of the entire digital printing machine were identified. In this study, investigation is conducted with LU focused on. It is important to understand vibration properties of LU to improve print quality. The vibration of LU is measured in operating conditions, and the vibration peaks are identified in some frequencies, where Frequency Domain Decomposition (FDD) is carried out. FDD method is used for the operational modal analysis and the dominant vibration components in printing status are extracted. From the results of FDD in vibration peaks, the influence of the vibration on print quality is studied. Comparing the results by FDD with those by excitation test, the influence of natural modes on the vibration in operation is investigated, and the excitation sources corresponding to vibration peaks are examined.

This paper presents a modeling approach for the galvano scanner to analyze the dynamic behavior during positioning. The galvano scanner requires high precision positioning and the flatness of the mirror to reflect the laser beam with precision. However, mechanical vibrations of the mirror, which are excited by the moment during positioning, lead to residual vibrations after positioning. These vibrations degrade the flatness of the mirror and the laser manufacturing accuracy. In this paper, the mechanism including the elastic bodies is modeled using a multibody dynamics software, while the control system is constructed on a control design software. Dynamic behavior of the mirror during actual motion can be visualized by integrating these software.

Axle weighing system measures axle weights of in-motion vehicles. A method has been studied for estimating axle weights by processing the weight signal to improve the accuracy of measured axle weights. The method has been applied to in-motion vehicles at the velocity of less than 15 km/h and axle weights have been obtained in high accuracy. However, the examination of the accuracy of estimated axle weights of in-motion vehicles with higher velocity has not yet completed. To examine and improve the accuracy of the estimated axle weight, miniature models have been developed. Through the experiments using these miniature models, motion data of vehicle body and weight signals have been obtained when the miniature instrumented vehicle passes on the weighbridge in various situations. Also, we have applied the estimation method to the obtained weight signals. This paper presents the basic idea of the estimation method and the results of the examination of the accuracy of the estimated axle weights.

There are much of traffic accidents occur at intersections. Then, it have been developed by the vehicle makers that the system avoid the crash to a parked vehicle or the pedestrian who is crossing the intersection. On the other hand, the collision between the vehicles are the commonly traffic accident in the crossing. However, there are no system to avoid the collision in the crossing. The purpose of the study is to develop the crash avoidance system in the crossing. we suggest the crash avoidance system by sharing drive information. The vehicles share the driving informations and the drive control informations. When the system predict the crash in the crossing, the system over ride the drive control and to avoid the crash. The outline of this system was showed in this report.

It can be used for design for improving ride quality by grasping vibration characteristics of human-wheelchair system and reveal the influence on ride quality. The purpose of the study is to reveal the influence of the vibration of the frequency input by wheelchair traveling on the road surface on human's vibration riding quality. In this research, frequency response experiment using vibration generator and experiment of evaluation of input vibration were performed. The influence of input vibration on human riding quality are revealed the relationship between vibration characteristics of human-wheelchair system and ride quality evaluation. As a result, the resonance of the human body and the peculiar resonance of the human-wheelchair system are able to confirm. The discomfort to vibration is due to the resonance of each part of the human body. Vibration of the chest as a body trunk greatly contributes to discomfort.

This paper deals with response behavior and rollover resistance of heavy duty truck in cornering. Our goal of research is to prevent the truck from rollovering by incorporating the rollover prevention device into the truck. In this study we investigate the behavior of the truck without such devices. The truck is expressed by nonlinear-four-wheel model that has 3 degree of freedom, that is, yaw angular speed, side slide angle, and roll angle. The equations of motion include the nonlinear property of the tire lateral force. This equation is solved by numerical calculation, and running locus and wheel load is caluculated. We use the rate of decrease of wheel load as the index for judging rollover. By comparing the linear model and the nonlinear model, we show the usefulness of the nonlinear model. Furthermore, we perform parametric study of running speed, steering angle and so on, and investigate the safe runnning condition.

Traction control is effective for avoiding wheel spin on a slippery road and stabilizing vehicle status. Verification of traction control for a motorcycle is more difficult than that of a four wheels car because the motorcycle has the risk of a turn-over accident. Based on this fact, this paper poposes HILS (Hardware-in-the-Loop-Simulation) for traction control of a motorcycle. It is mainly comprised of an actual motorcycle, a chassis dynamometer and a general controller performing traction control and a simulation model regarding vehicle dynamics. The most distinctive feature of the HILS is that the characteristic between tire and road surface is controlled by a difference of tire vertical force which is set by a crane hanging the rear part of the motorcycle. This HILS is tested with the traction control performed by fuel cut and verified its effectiveness to set characteristic between a tire and road surface.

MFP devices have a problem of paper jam. It is thought that the paper jam occurs due to a decline in frictional force of rubber rollers for feeding paper. Although the main cause of the decline is the adhesion of paper powder to rubber rollers, the mechanism is not detailed. By this reason, most of previous studies of numerical analysis on rubber rollers have not been capable of considering an influence of paper powder. In contrast, direct observations using microscopes are valid, however, microscopes require high resolution and wide field of view to observe centimeters-long rollers. In this study, as one of the approaches to solve the problem of paper jam, we observed the contact interfaces between rubber rollers and a glass plate using wide field of view laser microscope. After the observation, we logged torque applied until the macroscopic slip occurs. By this method, we quantified the real contact area and frictional coefficient between rubber rollers and a glass plate. As a result, we clarified that paper powder influence considerably the real contact area and frictional properties, and there is an interrelationship between the real contact area and frictional properties.

A laser micro texturing is one of the key technologies improving the friction properties. High friction is required for size reductions of machine elements or medical implants. For example, pedicle screws are implants for surgical treatment for idiopathic scoliosis patients especially of serious cases. Size reduction of this implant is required for better QOL of the patients. Biocompatibility is necessary for medical implants, however, it narrows the choses of materials and constraints the design. We developed the high friction surface by laser micro-texturing on practical implant surfaces. The surface has many micro-asperities, which deform and show high friction. In this study, the effect of laser micro texturing on the frictional properties were clarified. We have concluded that laser micro texturing is suitable for processing the asperities with high surface angle that increases the friction

This study developed an experimental method that can quantify tangential contact stiffness and friction damping characteristics of the contact interface between rough metal surfaces. The experimental apparatus employs a surface contact between two hollow disk specimens made of carbon steel. A tangential load, i.e., F, was applied at the contact interface, and the tangential displacement (deformation) of the contacting asperities within the apparent contact zone, i.e., u_a, was measured simultaneously. From the relationship between the tangential load and displacement, i.e., F vs. u_a plot, the tangential stiffness and friction damping characteristic were quantified. In this paper, the effect of normal load and roughness of contacting surfaces on these characteristics were investigated.

Recently, automobile engine is required smaller size and low fuel consumption for restraining global warming. These contributes into move frictions in harsh conditions for the plane bearings. Tribological characteristics such as wear resistance and seizure resistance are required for plane bearings. For this reason, resin overlay bearings are used in automobiles. However, due to the thermoplasticity of PAI, it is concerned that the mechanical properties may change under high temperature. In this study, we investigate the influence of heating temperature on the surface strength of resin overlay by performing reciprocating tribotests and SAICAS tests. In reciprocating tribotests, the wear resistance was improved by subjecting the test specimen to heat treatment. Also, the friction force increased in the area where the resin overlay was delaminated. In SAICAS tests, the shear strength of resin overlay decreased as the test temperature increased.

Recently, reducing mechanical friction loss of automotive vehicle has proceeded for countermeasures against global warming. Technology to improve fuel efficiency will contribute into worsening the piston environment. Therefore, it is required that tribological properties of piston sliding parts are improved. And, the DLC has begun to be applied to engine sliding parts. It is said that one of the causes of low friction is the formation of graphite-like low shear strength layer on the DLC. UV irradiation forms graphite-like low shear strength layer on the DLC. There is a report that the friction coefficient decreased for the UV irradiated DLC. However, it is not known about running-in and seizure behavior of it. The purpose of this study is to elucidate running-in and seizure mechanism of the DLC treated by UV irradiation. Tribological properties of UV irradiated DLC are evaluated by using a ring-on-plate tribometer. Friction test was started from low load and then, load was continuously increased. As a result, the initial friction coefficient decreased by about 50 %, and the running-in distance also decreased. Also, the steady-state friction coefficient of the UV irradiated DLC was lower than that of the UV unirradiated DLC.

Many printers incorporate heaters to fix ink on printing paper, increasing the power consumption of the printers. Currently, a novel power saving technology using a thermal print head instead of a heating roller has been progressed. However, there is concern that contact failure may occur with the heating system using the thermal print head because the thermal print head is constructed on a hard glass substrate and is hardly deformed. In this study, we aimed to establish a method of evaluating the performance of thermal print head by contact heat transfer simulation. First, we experimentally obtained the contact heat transfer coefficients under various contact pressures to consider the effects of the real contact area between the thermal print head and transfer belt. Then, we simulated the heat transfer process of the thermal print head, incorporating the relationship between the contact pressure and the contact heat transfer coefficient. We elucidated the contact heat transfer characteristics of the thermal print heads having four different kinds of structure and how heat was transferred through the contact interfaces.

It is important to evaluate contact strength, lifetime and radial rigidity of rolling bearings when to use them. Unfortunately, it is still difficult to do the evaluations accurately in theory because contact problems of the rolling bearings have not been solved accurately in theory when structural deformation of the whole bearing is considered. In order to be able to consider the structural deformation in bearing contact analysis, a new numeric method was presented in the last research based on the principles of mathematical programming method and three-dimensional, finite element methods (FEM). This paper uses the presented method and self-developed FEM software to investigate radial rigidity of a ball bearing. The contact stress and radial rigidity are analyzed using the self-developed FEM software and compared with the ones obtained by Hertz formulas. It is found that the results obtained by FEM are different from the ones obtained by Hertz formula. An experimental method and apparatus are also suggested to measure radial rigidity of bearings in order to identify which method is more accurate in contact analysis of the bearings.

We developed a gasket to seal even if the surfaces of the sealing land are not solid-contacted and examined the possibility to reduce the leakage from the land by controlling the viscosity of liquids. The test rig consisted of two metal disks, a Peltier module (83 W), a platinum resistance thermometer (Pt100), a reservoir, and a flow meter. The outer diameter and thickness of the disk was 200 mm and 10 mm, respectively. In the experiment, oil temperature, seal pressure (height: 0.5, 1.0, 1.6 m), land gap (0.05, 0.1, 0.2 mm), land size (40, 30, 20 mm), and oil type (VG22 and 46) were selected as the test parameters. The sealing land of the test gasket was cooled and heated and the leakage was measured. The experimental results revealed that i) the leakage was varied as the oil temperature and viscosity were changed, ii) the repeatability and reversibility of the phenomena were measured and confirmed, and iii) these results were obtained for all oils tested.

In this research, we are aiming at developing a support system for customer co-design. There are three major problems in customer co-design. (1) It is time-consuming to find a design plan that satisfies the customers' requests. (2) It is time-consuming to construct calculation workflows of the system. (3) It is time-consuming to develop customized GUI for each customer. To deal with the three problems, we have developed a customer co-design support system which has three features. (1) We use machine learning to learn the relationship between customer requests and product design parameters. (2) We develop a workflow constructor based on the open-source software KNIME to help the users construct customized workflows easily. (3) We develop a dashboard GUI builder. In the GUI builder, the most commonly used GUI components are registered and they can be reused easily. We applied our system to oil&gas application and verified that our system is useful in building customer co-design systems.

As the globalization of various industries continues, the achievement of more sophisticated functions, improved safety, and lower costs is required, particularly in the automobile industry, which is a representative manufacturing industry that has been the driving force behind the economic growth of Japan. Under such circumstances, there is much hope for the reduction of cost from defective work, achieved by implementing preventive measures for the recurrence of defects as a means for improving earnings. Although every company has been conducting various activities intended to reduce costs, not much progress has been made with the reduction of defects for molds because of various reasons.This paper deals with resin molds and develops the logic for automatically processing the trend analysis of the flaw in mold manufacturing and transferring that to knowhow. A matrix drawing is applied and a sophisticated information matrix about design requirements in mold production and molding try is defined. Then, the difficulties in the improvement of the flaw in the mold manufacturing are categorized. For the categories that are difficult to improve the flaw in the mold, the authors propose the logic for making knowhow by subdividing the category of failures and parts, and analyzing with sophisticated information.

This study aims at developing an analyses method for failure mode relating to material property by considering simulated design specifications of functional model. The proposed method contains the following procedure; 1.Composing a simulated design specifications of functional model, 2.Failure mode analyses by inserting deviation patterns to the design specifications, 3.Identifying failure modes and root cause analyses to identify failure causes relating to material properties. The proposed procedure was applied in a pilot study of a simplified laser irradiation machine. The group who used the proposed model based on DRBFM demonstrated a higher rate of successfully detecting person to material-relating causes, compared with the group who used conventional FMEA. Therefore, the proposed model effectively supports users to identify causes of failure modes relating to material properties for functional materials.

Machine screws less than M2.0 are increasingly used to assemble small electronic equipment and wearable terminals owing to the thinness and miniaturization of these devices. Defectiveness can easily occur in an assembly and the quality of the assembly is not guaranteed when thread tightening is performed by hand by many workers in a mass production line. Therefore, the automation of screw tightening using robots is advancing. On the other hand, an electric driver, which is controllable with the torque and turning angle by servo controlling a stepping motor has been recently developed. Screw tightening data is managed and quality certification by developing a traceability system is expected. In this paper, an experimental device to measure the fastening torque of the fastening working state of the machine screw and change in the axial force was designed to examine screw tightening conditions for machine screw tightening automation. It was verified that the fastening torque and axial force can be measured simultaneously using this instrumentation system in M2.0 and M1.2 screws.

Much emphasis is now being given to research and development of plant factories which daily produce large amount of high quality vegetables under artificially controlled environments. One of the important issues to be considered for the management and the daily operations of the plant factories is to find a set of suitable customers and/or markets to which the daily produced vegetables are sold and delivered. The current wholesale markets of the vegetables are not suitable for trading the high quality vegetables produced by the plant factories, therefore, a new market is required to sell and to buy the products made by the plant factories. A new trading market system is proposed, in previous research, to sell and to buy the vegetables supplied by the plant factories, based on the stock exchange mechanisms. In this research, a method is proposed to generate suitable selling and buying orders based on the yield rate and the demand estimations, aimed at reducing the losses due to unsuitable selling and buying orders in the proposed trading market.