材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
15 巻 , 151 号
選択された号の論文の8件中1~8を表示しています
  • 藤井 太一
    1966 年 15 巻 151 号 p. 209-218
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 池尻 忠夫
    1966 年 15 巻 151 号 p. 219-224
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    図1のような電極と絶縁材料との組合せ配置は, 実際の電気機器の構成においてよく見受けられるところで, その耐アーク性の評価は絶縁設計上重要な問題である. したがって, 数種の樹脂についてこのような配置のもとで耐アーク性試験を行なった.
    その結果, 次のような結論を得た. (1) 組合せ配置でのアーク抵抗は平板試料のそれの約30~50%まで低下する. (2) シリコーンゴムではエポキシ, ポリエステル樹脂より耐アーク性低下の割合は大きい. (3) 充てん剤の配合はアーク抵抗低減効果の改善にはあまり顕著な効果を示さない. (4) 角部C(同図)の曲率半径ρが大きくなるとアーク抵抗の低下は少なくρが0.5mmより3mmにまで増加すると1.4~1.5倍増大する. (5) アーク抵抗の低下は電界集中効果によるものと考え, アーク劣化の条件式を求めた.
  • 植村 幸生, 山城 貞男, 小林 政治郎
    1966 年 15 巻 151 号 p. 225-229
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    プラスチック材料のかたさ値は温度によって変化する. かたさの標準試験法を確立するためには, 標準状態 (JISでは20℃) 付近における温度によるかたさ値の変化に関する資料が必要である. 本報告は20±10℃の温度範囲において, 29種類のプラスチック材料のジュロメータかたさおよびバーコルかたさについて実験を行なったものである. その結果は概略次のようである. 例外なく温度上昇とともにかたさ値はほぼ直線的に低下する. その低下量は同一のかたさスケール内ではかたさ値の高いものほど少ない. すなわち, かたさ低下率α (かたさ値の単位/℃) はくぼみ深さ (=圧子侵入量) とほぼ比例関係にある. したがって, 20℃におけるかたさ値に対応するくぼみ深さに対するかたさ低下率αの割合を意味するくぼみ変化率β (単位は1/℃) は, かたさのスケールごとにほぼ定数とみなせる. このことは測定時の温度差から生ずるかたさ値の誤差の簡易補正法として利用できる. 単位かたさの変化をひき起こすに要する温度差を表わす温度影響率γ (℃/かたさ値の単位) は, 二, 三の例外を除き1以上である. したがって, 試験条件としての試験温度に対する許容誤差は±1℃が適当と考えられる. ただし, それぞれのかたさスケールでかたさ値が50~60以上のかたさ値の高い材料に対しては許容誤差を±2℃としてもよい.
  • メッキ条件と疲労強度
    砂田 久吉
    1966 年 15 巻 151 号 p. 230-235
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    It is well known that the fatigue strength of machine part is generally reduced when plated with Chromium. But for nickel plating of steel there have yet been but scanty data for ensuring the effective fatigue strength. The author has investigated on that account the effect of nickel plating on the fatigue strength of carbon steel.
    The fatigue test specimens used in the present experiment were 10mm in diameter, and were made of annealed 0.15%C steel or annealed and quenched-tempered 0.45%C steel. The nickel plating of these fatigue test specimens was carried out in the Watt's type bath, having the composition NiSO4·7H2O 240g/l, NiCl2·6H2O 45g/l, H3BO3·30g/l. Then the current densities were 1.0, 0.7, 0.5A/dm2, and the bath temperature was kept at 25°C.
    The results obtained can be summarized as follows.
    1) The higher the fatigue limit is in unplated steel the lower the limit is in nickel plate steel, no matter what the plating condition is.
    2) The higher the plating current density is the larger the drop of the fatigue limit in nickel plated steel is. It is considered that this is closely connected with the presence of residual tensile stress in the plated layer.
    3) Moreover, the drop of the fatigue limits in the nickel plated steel is influenced by the plate thickness. The increase of the plate thickness lowers the fatigue limit. This is probably the notch effect due to the rough plate surface and to the crack in the plated metal.
  • 片振引張りの場合
    加賀屋 繁治
    1966 年 15 巻 151 号 p. 236-243
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    The fatigue tests of materials using objects in practical use as specimens are remarkably common in recent years.
    Larger amplitudes are required in the fatigue tests, therefore, both of stress and of strain.
    When there is large deflection of specimens in the test made by means of a hydraulic large-fatigue testing machine, it is necessary to reduce the load repetition cycle.
    In this kind of testing machine either electrical or mechanical, the prime mover that is in common use is capable of adjusting speed within the range about 1:4.
    The driving torque of these prime movers is almost constant at any speed.
    At low speed, therefore, both the power produced by this prime mover and the effect of the fly wheel are smaller than those at high speed.
    At low speed, moreover, the driving shaft of the machine receives shock due to the large reversed torque created by the reaction of the specimen.
    In the present paper, the author has worked out the analysis of the mean torque of the hysteresis loop of the specimen and the reversed torque caused on the driving shaft by the compressibility of oil in the hydraulic system.
    In order to keep uniformity against the varying torque, he installed an accelerative fly wheel capable of being switched to the driving shaft to change the gear ratio.
    For the purpose of increasing both the mean torque and the starting torque, he introduced an improvement on the mechanical gearing system particularly to prevent the shock of reversed torque effectively when the machine is operated at low speed.
    By adopting these new devices into the fatigue testing system, it is made possible now to enhance its capacity and to reduce the electric power consumption.
  • F. BOLLENRATH, V. HAUK, E.H. MÜLLER
    1966 年 15 巻 151 号 p. 244-246
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 作井 誠太, 中村 正久, 津村 利光
    1966 年 15 巻 151 号 p. 247-253
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    The large impact torsion testing machine which has recently been designed and constructed by the present authors, has the capacity of 100kg-m and the rotating speed from 100rpm to 2600rpm. This machine is fit to make intermittent loading, the detection of axial stress caused during the torsional deformation and the tests under combined stress by adding tensile deformation.
    The blue shortness and the reduction of twist ductility during the α-γ transformation of mild steel and 13% chromium stainless steel have been studied under various deformation rates. The brittle fracture of thin walled tubular specimens of mild steel with several grain sizes has been tested under various strain rates and low temperature, and the transition temperatures have been compared with that of impact tension and Charpy test. Finally the intermittent impact torsion has been carried out in order to evaluate the hot-working behavior of mild steel.
  • 上野 昭一, 大江 武, 山崎 博章, 伊藤 勝彦
    1966 年 15 巻 151 号 p. 254-260
    発行日: 1966/04/15
    公開日: 2009/06/03
    ジャーナル フリー
    Experimental studies have been made for the retentivity of polycarbonate in processing the material under uniaxial compression in the temperature range from cold to warm.
    The“Solvent Method”polycarbonate“Iuplion”was used as test specimen. The strain recovery of the test specimen compressed at various processing temperatures was measured by free annealing at the temperatures higher than the processing temperatures. It has been revealed that the strain recovery is complete when the annealing temperature is higher than the glass transition temperature of the polymer, though the polymer has excellent cold processing ability of freezing the strain when the temperature is lower than the glass transition temperature.
    A new“Modified Erichsen”testing apparatus was proposed for measuring the temperature dependence of the processing ability of sheet plastics in relation to the cold and warm processing of the polymer. Sheet specimen was penetrated by a solid punch at constant rate of stroke at various temperatures and the penetration depth at fracture was measured. The processing ability of polycarbonate sheet (1mm thick) was gradually improved as the increase of the temperature up to the glass transition temperature.
    The strain recoverey in the Erichsen test was examined in the same way as the uniaxial compression test, and a well parallelism between the results obtained under a combined stress such as the Erichsen bulging and those under an uniaxial compression as the above was found.
    Test specimen worked by the“Modified Hot Erichsen”testing apparatus is being intended to be available for the environmental stress cracking test of the polymer.
feedback
Top