Transactions of the Japan Society of Mechanical Engineers Series C
Online ISSN : 1884-8354
Print ISSN : 0387-5024
Volume 55, Issue 518
Displaying 1-25 of 25 articles from this issue
  • Shigeo YAMASHITA, Katsumi SAWATARI, Kazuto SETO
    1989 Volume 55 Issue 518 Pages 2511-2518
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper shows the design method for constructing the piping system with well-suppressed resonance peaks through the wide range of frequency. The piping system is strongly influenced by sources of excitation for blade vibrations since it is usually made flexible and has a low damping property. Thus, many problems, like fatigue damage or noise caused by vibration, happen frequently in the piping system. In order to suppress resonance peaks and obtain high damping in them, dual dynamic absorbers proposed in the previous paper applied. In this paper, it is confirmed theoretically by the transfer matrix method that the piping system with seven resonance peaks within 100Hz is well suppressed by using five dynamic absorbers. The effectiveness of the five optimally designed dual dynamic absorbers is also demonstrated experimentally.
    Download PDF (818K)
  • Naoya KOJIMA, Kuniaki KAIHARA, Hirotsugu FURUYA, Hai ZHOU
    1989 Volume 55 Issue 518 Pages 2519-2526
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In approaches to finding noise and vibration control of machinery, measurement of the vibration energy flow in the structure can give useful information about vibration properties and noise generation mechanisms. This energy flow within the structure is denoted by the vibration intensity vector. By tracing back in the direction of this flow, it is possible to clarify the transmission path of the vibration energy and the location of the exciting source which most affects the response at each point of the structure. In this paper, the vibration energy flow delivered by the impulsive excitation excitation force is measured for a response necessary for a rectanguler plate in the presence of background vibration. The conditions of signal processing of the response necessary for accurate measurement of the vibration intensity vector are also discussed. The direction of the vibration intensity vector is then detected at some points in an operating diesel engine structure and was demonstrated in a valve-sheeting impact.
    Download PDF (908K)
  • Takuzo IWATSUBO, Hao-Tai NAN
    1989 Volume 55 Issue 518 Pages 2527-2533
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    There are many papers dealing with the vibration and noise of a geared-rotor system. Most of them, however, do not refer to the relations between the location of noise occurrence and noise propagation. In this paper, by using the sound intensity method, locations of noise occurrence and characteristics of noise propagation were investigated by measuring the sound power and the sound intensity. As a result. noises caused by the vibrations of the rotor and the gears, and each characteristic of noise propagation were clarified, and it was verified that the sound intensity methodis suitable for the study of the vibrations and the noises of the geared-rotor system.
    Download PDF (798K)
  • Hisami OHISHI, Shinichi OHNO
    1989 Volume 55 Issue 518 Pages 2534-2539
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A method of estimating the pressure of structure-borne sound included in noise radiated by an enclosure containing a machine that produces both noise and vibration is proposed. In this method, estimation is carried out using accelerations measured when the machine is in operation and transfer functions determined when the machine stops its operation. Specifically, the accelerations are ones measured at the points on the enclosure where the machine is connected to the enclosure, and the transfer functions are ones determined as complex ratios of the accelerations at the connecting forces to the connecting points from outside the enclosure. First, the theory of the method is derived and then its validity is the method is derived and then its validity is ascertained by experiments.
    Download PDF (710K)
  • Kazuo MANO, Zenta IWAI, Atsushi OHOTOMO
    1989 Volume 55 Issue 518 Pages 2540-2546
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In this paper, a robust control design is developed for multi-joint manipulators using a sliding observer. The sliding observer, the basic idea for which was proposed by Slotine et al., is introduced to estimate the angular velocity of the links under the disturbance input. The sufficient condition for a sliding mode to exist and for the state to reach a sliding plane is derived in this paper. The feedback control is designed by use of the estimated value of the angular velocity θ·A relay control law is shown to ensure the robustness concerning the disturbance inputs. To illustrate the effectiveness of the proposed method, a computer simulation is performed for a two-joint manipulator.
    Download PDF (652K)
  • Kohichi SUZUMORI
    1989 Volume 55 Issue 518 Pages 2547-2552
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A flexible microactuator with 3 degrees of freedom has been developed for Micromanipulators. It is made of fiber reinforced rubber and its deformation is controlled by an electrohydraulic or - pneumatic system. This report deals with its static characteristics. First, theoretical characteristic equations are derived based on the infinitesimal deformation theory. They are useful for practical design applications due to their simple forms. Secondly, the FEM is applied to the nonlinear analysis of large deformation. The calculated results are compared to the experimental data of the prototype (outerdiameter: 12 mm, length: 50 mm). As a result, while the theoretical characteristic equations are effective for predicting small deformation, the numerical method is for both small and large deformations.
    Download PDF (665K)
  • Toshinori SUEHIRO, Fujio OHKAWA, Kenji KUROSU, Tadashi YAMASHITA
    1989 Volume 55 Issue 518 Pages 2553-2558
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper describes the application of a Model Reference Adaptive Control System (MRACS) to the positioning control and the force feedback control of a flexible arm. The flexible robotic arm is simply modelled as flexible cantilever beam revolving at a joint. The mathematical models of the flexible beam for positioning and force feedback are induced as a lumped parameter system. By discretizing these models through a sampling period, discrete time equations are obtained and a discrete MRACS is designed for each discrete model. A set of experiments is carried out to examine the effectiveness. In the experiment for positioning cotrol, a CCD camera and image processor were used to measure the position of the tip of the beam. In the experiment for force feedback control, a load cell was used to measure the force acting on the end of the beam. A dc servo motor was used as an actuator. The adaptive control system can be designed by the simple algorithms and structure. Experimental results have shown that the control performance is good and the constructed MRACS is effective.
    Download PDF (602K)
  • Shitta SHINGU
    1989 Volume 55 Issue 518 Pages 2559-2568
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    Graphical synthesis of the actuator system in the magnetically suspended positioning mechanism is realized, and its functional sufficiency is confirmed using linear algebra. Decoupling characteristics in the Cartesian coordinate system in spite of the strong coupling in the local coordinates were shown realizable by a mechanism structural design, that leads to a simple-structured, effective positioning, vibration-free and reliable mechanism. The basic dynamic equation which allows the systematic design of the dynamic characteristics of the total system was formulated. The design method in this report attaches importance to practical applicability, conditions for practical use are taken into consideration.
    Download PDF (1078K)
  • Yohji OKADA, Eiichi SUZUKI, Kenichi MATSUDA
    1989 Volume 55 Issue 518 Pages 2569-2574
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    One of the biggest problems of realizing the fast motion of a robot manipulator is its dynamic reflection. The driving torque calculated from the mathematical model well compensates for this reflection. However, the dynamic property changes according to the clamped load and arm position. This paper introduces a high-speed adaptive control technique using identification. First, the manipulator is controlled only by a planned trajectory. A time domain identification is then applied to estimate the robot dynamics. The inverse transfer function is used to calculate the actuating signal which produces the high-speed motion of the next cycle. The proposed technique is applied to 3-dimensional positioning of a multijoint manipulator.
    Download PDF (642K)
  • Junji FURUSHO, Akihito SANO, Akihiro GOTO
    1989 Volume 55 Issue 518 Pages 2575-2582
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    It is generally recognized that cursorial animals possess off-road mobility characteristics far superior to those of conventional wheeled or tracked vehicles. In this paper, a control method for speedy quadruped which is based on free movement in a gravity field and saves energy. In the supporting phase, the waist joints are under an open-loop control which consists of two control modes: 1) a free rotation mode and 2) a constant voltage mode. The stability of the proposed method is examined by numerical analysis. The walking robot"COLT-1"is able to achieve average speed of 0.5 m/s by using this control method.
    Download PDF (923K)
  • Yasutsune ARlURA, Tsutomu NAKANISHI, Syuhei KUROKAWA
    1989 Volume 55 Issue 518 Pages 2583-2586
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A method of evaluating the tooth bearing of cylindrical gear pairs is proposed. First, a program is developed for simulating the tooth bearing numerically considering a tooth flank configuration, which is given by tooth profiles and lead curves, and an alignment error, which consists of shaft angle error and center distance error. In this paper, the contact patterns of gear pairs with a certain error under no load are calculated using this program. Secondly, the contact patterns of a pair of cylindrical gears are measured by adjusting the alignment. Comparing the contact patterns obtained by experimentation with the calculated ones under the same condition as in the experiment, we find that they agree with each other closely. This agreement can be hardly obtained when contact patterns are calculated without the tooth flank configuration error and the alignment error. In conclusion, the result shows a state of engagement of practical gear pairs with errors, and it is found that this is a valid method for evaluating the tooth bearing of cylindrical gear pairs
    Download PDF (555K)
  • Satoshi ODA, Koji TSUBOKURA, Takao KOIDE
    1989 Volume 55 Issue 518 Pages 2587-2590
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper presents a study on the impact and bending fatigue strength of case-hardened gears with various case depths at low temperature (-60°C). For this experiment were used gear-impact testing equipment and a gear-bending fatigue testing machine of hydraulic loading type with a cooling chamber, which were developed by the authors. The impact and bending fatigue strength of case-hardened gears at room and low temperature, and the effects of case depths on these strengths were clarified considerably.
    Download PDF (494K)
  • Akira YOSHIDA, Yuji OOUE, Takafumi HARA, Koumei FUJITA, Kiichi MIYANIS ...
    1989 Volume 55 Issue 518 Pages 2591-2598
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In order to elucidate the effects of the hardened depth and relative radius of curvature on the surface durability of carbonitrided steel rollers, chromium steel rollers with diameters of 30, 60 and 120 mm were fatigue-tested with pairs of the same diameter rollers under a sliding-rolling contact condition. The experimental results were discussed by the amplitude of the ratio of shear stress to the Vickers hardness. The surface failure mode in this experiment was spalling due to the subsurface cracking. The depth of the spalling crack agreed with the depth of the maximum amplitude of the ratio of shear stress to the Vickers hardness. The surface durability of the carbonitrided roller tended to increase as the hardened depth increased and the relative radius of curvature decreased.
    Download PDF (1044K)
  • Nobutoshi OHASHI, Masaya HAGIWARA, Isamu YOSHIMOTO
    1989 Volume 55 Issue 518 Pages 2599-2604
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    The standardization of a fatigue testing method is very important for collecting fatigue strength data for threaded fasteners. The Japanese Industrial Standard on this testing method was published by taking account of the ISO Standard and the JSME Standard. In the procedure of drafting the above JIS, the experimental research and statistical discussions were conducted and the main conclusions are as follows: (1) Three companies in the first-step experiment and six companies in the second-step experiment performed the fatigue tests, and no confusion resulted in the application of the 14 S-N testing method according to the JSME Standard. (2) Based on the 14 S-N testing method, the experiments of the one-way classification model and the two-way classification model were performed, and the method of analysis of variance for such experimental results is shown.
    Download PDF (693K)
  • Masaya HAGIWARA, Kanefumi NAKAHARA, Isamu YOSHIMOTO
    1989 Volume 55 Issue 518 Pages 2605-2610
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This study deals with X-ray measurement of residual stress at the local area around the thread root of a bolt. Residual stress in the 0.5 mm×5 mm area was measured using a method of stepped scanning and parabolic approximation. The conditions of measurement had been determined and evaluated through the preliminary measurement of compressive stress acting on the cylindrical surface. Furthermore, the fatigue strength estimated by applying the residual stress data to the previously presented hypothesis was compared with the experimental results. The main conclusions obtained were as follows: (1) The residual stress in a relatively small area on the cylindrdcal surface with large curvature can be measured by X-ray using a method of stepped scanning and parabolic approximation; (2) The compressive residual stress measured at the thread root was larger for the bolt manufactured by thread rolling after heat treatment than for one manufactured by thread rolling before heat treatment; (3) The distribution of residual stress along the axial direction from the thread root to the portion under crest did not represent remarkable change in its value; (4) The residual stress of a bolt was somewhat decreased by fatigue loading on the condition of low mean stress; (5) The fatigue strength estimated using residual stress data showed the tendency of experimental results well.
    Download PDF (749K)
  • Chuji MIYATA, Tosimitu TUMURA, Isao IWATO
    1989 Volume 55 Issue 518 Pages 2611-2617
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    The stress distribution in a bolted joint and the pressure distribution on the bearing surface of a hexagonal flange nut have been examined by the three-dimensional photoelastic experiment. The experiment shows that the stress distribution in a bolted joint is axially asymmetrical, because the screw part has an axiasymmetrical shape. The pressure distribution on the bearing surface of hexagonal flange nuts has the asymmetry corresponding to that stated above. The radial distribution of the bearing surface pressure concentrates at the inner part of the flange, while the pressure on the bearing surface at the outer part of the flange is reduced to almost zero. Namely, the pressure on the bearing surface of the hexagonal flange nuts is not uniformly distributed. In the case of a nut having some part without the thread, i. e, an improved nut with the skirt, the peripheral portion of the nut can bear the load pressure which has uniform distribution in all directions of circular angles. Thus the cause of loosening due to asymmetrical distribution of pressure on the bearing surface is eliminated.
    Download PDF (890K)
  • Yuji YAMAMOTO, Masaaki HASHIMOTO
    1989 Volume 55 Issue 518 Pages 2618-2624
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    Changes in surface properties during the running-in process, especially those in surface topography and surface hardness, were examined using a two-disc type of machine. The loads applied were lower than the shakedown limit of a test material. Two differen running-in tests were conducted i. e. a low-speed test in which the in which the contact condition was severe, even at an initial stage, and a high-speed test in which the initial thick oil film thickness became thinner and the contact condition became more severe with time. After running-in, the roughness and correlation distance of disc surface were reduced and increased, respectively. The final surface topography was controlled by the initial surface topography and the final film parameter. The surface hardness was also increased after running-in. Consequently, the scuffing resistance of discs was enhanced through the running-in process. The high speed test was excellent in improving surface topography and increasing surface hardness compared with the low speed test where the wear of rubbing surfaces was increased.
    Download PDF (909K)
  • Norio TAGAWA, Masanobu HASHIMOTO
    1989 Volume 55 Issue 518 Pages 2625-2631
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper proposes a self-loading flying head slider mechanism to be used for information storage on magnetic disk media under non-contact start/stop mode conditions. The mechanism consists of a zero-load negative pressure air bearing slider, a slider suspension mechanism and a twin-structure piezoelectric actuator as the head loading mechanism. Experimental research on fundamental flying characteristics of the slider was carried out. The dynamics of a self-load/unload negative pressure air bearing were successfully studied in detail with a laser Doppler vibrometer, and no intermittent contact between head and disk was observed in either the self-load or unload case. A theoretical study of the self-loading phenomenon was performed, and its conclusions were in good agreement with the experimental results. This suggests the feasibility of achieving a high head/disk interface reliability and, in particular, of overcoming problems of stiction and tribology between head and disk.
    Download PDF (817K)
  • Geui-Sik CHUN, Suk NAMGUNG, Yoshimi ITO
    1989 Volume 55 Issue 518 Pages 2632-2636
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In order to assure system reliability in FMS and unmannned machining, automatic sensing devices are required. The in-process recognition of chip forms is one of the most important technologies for the completely automatic operation of machine tools. In this study, the dynamic component of cutting force closely related to chip breaking has been measured to recognize chip forms. From the measured results on various cutting conditions and tool geometries, especially those having crater wear, the relationship between the chip form and the dynamic component of cutting force has been investigated. As a result, it can be verified that the dynamic component of cutting force adequately processed using the cut-off frequency (80-500 Hz) reflect exactly the conditions of chip breaking, and has a periodic component. Accordingly, it is possile to recognize the states of chip formation, and to tell which chips can be easily handled, by monitoring the maximum amplitude of the dynamic component of cutting force.
    Download PDF (672K)
  • Shinobu SATONAKA, Itsurou TATSUKAWA, Mitsuharu YAMAMOTO, Taisei UENO
    1989 Volume 55 Issue 518 Pages 2637-2641
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In the conventional ultrasonic inspection of cast iron, a dead zone of probe and surface roughness makes ultrasonic inspection of near-surface flaws such as blow holes and pin holes difficult. In this paper, an improved technique of ultrasonic inspection using a focusing probe is applied to various types of artificial defects in cast iron. The results show that with a water distance such that the focal point of the ultrasonic beam locates beneath the flaw, echo of the near-surface echo on an A-scan display. The surface roughness causes the echo height of both surface echo and flaw echo to fluctuate, but their fluctuations become smaller with decreasing water distance. The scanning graphs of flaw echo height show a wavy pattern and a flat-shaped pattern reflected from the small flaw and plane flaw, respectively. The C-scan display is an effective method for presentsing the distribution of flaws.
    Download PDF (730K)
  • Hiroaki FUNABASHI, Mikio HORIE, Hiroshi TACHIYA, Satoshi TANIO
    1989 Volume 55 Issue 518 Pages 2642-2648
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    Kinematic and static characteristics of pantograph mechanisms have been analyzed and represented in the form of charts which enable rational syntheses of the mechanisms as robot arms and legs with two degrees of freedom. Namely, two factors concerning the maximum joint forces and bending moments of links when the mechanisms take arbitrary positions and attitudes have been proposed and the positions of output points where the each factor takes various values are plotted in dimensionless reachable regions of the output points. Making use of the characteristic charts, dimensions of working spaces, loading conditions, strokes and arrangement positions of actuators etc. can be directly considered in the determination of kinematic parameters of the robot mechanisms with the optimum joint forces and bending moments of links.
    Download PDF (805K)
  • Norihiro NAKAJIMA, Shinji TOKUMASU
    1989 Volume 55 Issue 518 Pages 2649-2656
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A modelling method, which generates a computational mechanics model, is suggested for mechanical design work. The design model is described by three kinds of data : geometric data, structural data, and product data. It is applied to generate the computational mechanics model automatically by the newly developed, extended quad/oct tree method for discretized mesh generation and numerical analyses data generation. The extended quad/oct tree method automatically generates suitable meshes for either FEM, BEM, or FDM. Suitable meshes mean that a fine mesh is generated where it should be and a coarse mesh is generated at areas outside the points of interest in the analysis. The data for problem specification in the analysis are translated from product data automatically and preserved with the quad/oct tree structure in order to inherit the data to the branches. The preserved data are utilized especially for an h-version of the remeshing process.
    Download PDF (1026K)
  • Tetsuo SHIMADA, Yukio TADA
    1989 Volume 55 Issue 518 Pages 2657-2662
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper described a new scheme of 3D object modeling using a finite element method. When designing a curved surface, We need to consider the following processes. First, various regions on a curved surface are transformed into flattened forms. Second, a curved surface is recovered from the flattened form. Third, the corresponding curved surfaces have to be made based on modified flattened shapes. we have already proposed a method to develop any curved surface using the finite element method. In this paper, We deal with recovery of 3D shapes from flattened ones and some additional information. Examples about a body of axial symmetrical revolution and a shoes model are presented as typical and practical applications to illustrate the method that recovers 3D curved surface based on FEM.
    Download PDF (668K)
  • Yoshinobu SATO, INOlUEKoichi
    1989 Volume 55 Issue 518 Pages 2663-2671
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In this paper, the architecture of Hazard Control Systems (H. C. S. 's) for mobile robots is discussed based on an A-C Model H. C. Conceptual Design Method. First, two hazards that are typically produced in mobile robot systems are identified. These hazards are"Robot Collision against a Mobile Object". Second, Hazard Restrant Principle (H. R. P) 3 is applied to mobile robot systems for conceptualization of H. C. S. 's involve the following dissociation forms: 1) Stop by braking; 2) Stop by braking control against skid; 3) Stop by multicontrol against turnover; 4) Course control against a single static object ; 5) Course control against multiple static objects; 6) Multicontrol against multiple mobile objects. Then, the applicability of Danger-detection Information Processing Systems or Safety-confirmation Information Processing Systems is examined. Last, the relationships among whole-hazard space, the subhazard spaces where the identified hazards exist, the subhazard spaces where these Information Processing Systems are applicable in principle, and the dissociation forms are represented schematically.
    Download PDF (1037K)
  • Masashi SATO, Tomokazu MATAKE
    1989 Volume 55 Issue 518 Pages 2672-2675
    Published: October 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    Periodic step forces which were obtained from a large force plate were expanded in Fourier series. The relative velocities and the relative displacements of the center of gravity of a human body were obtained by integrating those Fourier series. It was emphasized that the walking state diagrams, that is, Lissajous' figures of those step forces, relative velocities and relative displacements were available to analyze the characheristics of waling. The even terms of the Fourier coefficients of antero-posterior step forces were large and implied symmetry of right and left step forces. The odd terms of those were small and implied nonsymmetry of right and left step forces. The ratio of the even-numbered Fourier coefficients to the total amplitudes of the relative velocities of the center of gravity in antero-posterior direction was linear to the walking speed.
    Download PDF (500K)
feedback
Top