日本フルードパワーシステム学会論文集
Online ISSN : 1349-7022
Print ISSN : 1880-3121
ISSN-L : 1349-7022
40 巻, 2 号
選択された号の論文の3件中1~3を表示しています
研究論文
  • 門田 和雄, 齋藤 靖之, 川嶋 健嗣, 香川 利春
    2009 年 40 巻 2 号 p. 17-21
    発行日: 2009年
    公開日: 2012/01/27
    ジャーナル フリー
    The applications of pneumatic artificial muscles (PARM) are increasing in the power assist and manipulator systems, because of its advantages such as high power-to-weight ratio and flexibility. Usually, we have to measure the contract ratio of PARM using a displacement sensor installed near the actuator which is not easy to make dust and water proof. In this paper, we propose an estimation method of the contract ratio from the volume change of the PARM which can make the actuator part sensor-less. The air charged and discharge to the PARM is measured by a quick response laminar flow meter. Then, the volume of the PARM is estimated from the flow rate and the pressure measured by a pressure sensor. In order to estimate the contract ratio accurately, thin copper wires are stuffed to the PARM to produce an almost isothermal condition during the charge and discharge. The effectiveness of the proposed method was confirmed experimentally.
  • 眞田 一志, 黄 鋭
    2009 年 40 巻 2 号 p. 22-29
    発行日: 2009年
    公開日: 2012/01/27
    ジャーナル フリー
    A simulation model of a cushion mechanism for an arm cylinder of construction machinery is proposed. As a cushion mechanism, a cushion-plunger type is studied. Annular clearance around the cushion plunger is modeled by a series connection of annular-flow sub-models. By use of the cushion model, diameter distribution of the plunger can be designed so that piston velocity follows a pre-specified velocity profile as close as possible. Applying the optimum design technique, a cushion plunger was manufactured and was installed in a cylinder. As results of experiments on a test bench, the simulated results of piston velocity showed a good agreement with a pre-specified velocity profile. The model and the optimum design technique are very useful tools for design of cushion mechanisms.
  • (斜板式アキシアルピストンポンプ・モータに用いられるスリッパのモデリング)
    風間 俊治
    2009 年 40 巻 2 号 p. 30-35
    発行日: 2009年
    公開日: 2012/01/27
    ジャーナル フリー
    A thermohydrodynamic lubrication (THL) model of hybrid (hydrodynamic/hydrostatic) thrust bearings for a slipper of swashplate type axial piston pumps and motors is developed. The generalized Reynolds equation, three-dimensional energy equation and heat-conduction equation are derived, and the physical properties (density, viscosity, speci.c heat at constant pressure, thermal conductivity and thermal expansivity) of a hydraulic oil are considered as functions of temperature and pressure. The equations are solved numerically, and the THL solutions of the slipper model are compared with the isothermal solutions and the solutions of the circular thrust pad hydrostatic bearing. The e.ects of the physical properties, the revolution radius and the slipper spin on the temperature distribution, temperature rise, clearance shape and power loss are examined for both of the THL and isothermal analyses. The physical property changes in.uence on the characteristics of the slipper model rather than the characteristics of the circular pad bearing model. The THL solutions indicate that an increase in the revolution radius causes an increase in the .lm temperature and the pad inclination.
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