Journal of the Japan Society of Precision Engineering
Print ISSN : 0374-3543
Volume 30, Issue 358
Displaying 1-9 of 9 articles from this issue
  • [in Japanese]
    1964 Volume 30 Issue 358 Pages 833-837
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
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  • Compression Shearing
    Hidetsune Hojo
    1964 Volume 30 Issue 358 Pages 838-844
    Published: November 05, 1964
    Released on J-STAGE: January 27, 2010
    JOURNAL FREE ACCESS
    A new shearing method, of which characteristic exists in the application of an axial force normal to the sheared profile, was developed together with the clarification of its shearing mechanism. The results obtained are as follows :
    (1) As the compressive axial force increases, the angle of first microcracks, α, decrease, while the specific shearing force, kc, produced in the moment of occurrence of first microcrack increase.
    (2) When the absolute value of stress, σx′, induced by an axial force becomes about two times as large as that of k, the direction of first microcrack in the thickness center becomes normally to the plate surface, and [kc]/[kc]σx=0 takes a value of 1.62.3.
    (3) The analytical results above mentioned agree with the experimental ones fairly well.
    (4) The quality of sheared parts is remarkably improved by a compressive axial force, while the shearing force is reduced by a tensile axial force.
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  • Yoshinobu TANAKA, Hideo TSUWA, Suehisa KAWAMURA
    1964 Volume 30 Issue 358 Pages 845-850
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    The experimental approaches are carried out on the problems of cutting edges, such as distributions and wear of them, under the conditions that there are relative vibrations between grinding wheel and the workpiece.
    It is shown that, as their amplitude increase, asymmetry of the distributions of cutting edges as well as wear of the grinding wheel are promoted notably.
    Wear of the grinding wheel reduce their amplitude, but when there are more than 3 μ of amplitude, that effect hold out till the life time of the grinding wheel.
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  • Theoretical Analyses on the Grinding Temperature (1st Report)
    Koya TAKAZAWA
    1964 Volume 30 Issue 358 Pages 851-857
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    Theoretical analyses of the grinding temperature have been attempted by many investigators, but are not sufficient.
    In this report, first, the technical problems on measuring method of the temperature distribution in ground surface layer are explained and the measured results are shown.
    And then, the theory of its temperature distribution is explained and the problems to be considered when applying this are pointed out.
    Theoretical equation of the temperature distribution in ground surface, obtained by applying Jaeger's heat transfer theory involving a moving heat source, in as follows.
    Θzmax·πκυ/2αqK=3.1L0.53e-0.69L-0.37Z
    where
    Θzmax : the peak temperature at any point in ground surface layer
    υ : the work speed
    κ : the thermal conductivity of the workpiece
    K : the thermal diffusivity of the workpiece
    α : the flowing rate into the work of the heat capacity generated by grinding
    q : the heat capacity per unit area generated by grinding
    Ll/2K, Zz/2 K
    l : the contact arc length between the grinding wheel and the work
    z : the depth from the ground surface.
    When numerical values are used, they are always in c. g. s. units.
    By this equation, the influence of the grinding conditions on the temperature distribution in ground surface layer is able to be investigated.
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  • Jiro NARA
    1964 Volume 30 Issue 358 Pages 858-863
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    A method of examining the existence of the periodical component on surfaces finished by abrasive grains or with other methods are considered by applying the stochastic process analysis.
    According to the results of this consideration, the following precautions are necessary in the evaluation of the surface characteristics.
    1) The existence of the periodical component must be objectively assessed with reference to the magnitiude of the confidence band of the power spectrum.
    2) Because the interval between the measuring points Δχ and lag number τ influences on the resolvability of the power spectrum of the surface, their values must be selected according to the object of observation.
    3) The sampling length of the profile curve used for the analysis must be chosen so that required property of the surface can be assessed with necessary precision.
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  • Iwao YAMAMOTO
    1964 Volume 30 Issue 358 Pages 864-870
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    Although ordinary pneumatic micrometers with higher gauge pressures are most adaptable types for industrial measuring instruments, they have comparatively large measuring force and have little linear parts in their transfer characteristics. Described in this paper is a method for improvement of performances of the pneumatic micrometers.
    Trially manufactured apparatus is composed of two single pneumatic micrometer circuits, one, lower pressure type pneumatic micrometer having a jet nozzle held by a spring-bellows transducer for negative feedback, serves as a preamplifier, and the other, higher pressure type pneumatic micrometer single circuit connected in cascade to the former through a pressure displacement transducer, serves as an output amplifier.
    The transfer amplification factors are given as K*/S when K* is a spring constant of the feedback transducer and S is a bellows effective area of pressure. Experiments conducted by using spring assembly, which is composed of eight compression springs, proved that more than 93% range of full scale is linearised with accuracy of less than 1 % in its static transfer characteristics and measurement under constant low measuring force less than 2g is performed. Also discussed are dynamic characteristics and the effects upon changing the circuit components.
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  • Maching Energy and Collision Velocity
    Genrokuro NISHIMURA, Yasuo YOKOYAMA
    1964 Volume 30 Issue 358 Pages 871-875
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    Basing on the tool's collision velocity υ0 obtained theoretically in the 1 st report, the present paper considered the machining energy E that is the energy consumed for machining, and also the repulsion coefficient α which is related to the machining energy. The paper, furthermore, discussed the machining energy which may be influenced by the exciting force F0, the frequency f and also the amplitude ratio γ respectively. The main results obtained in this paper are as follows :
    (1) When the collision velocity becomes a definite magnitude, the repulsion coefficient becomes the minimum and the machining energy the maximum simultaneously. The collision velocity giving this maximum machining energy is called by the name of Limit Collision Velocity in this paper.
    (2) The machining energy is given theoretically by the following expressions : When |υ0|≤|υL|, E= (η/8)·F02·(1-γ2) / (mf), and when |υ0|≥|υL|, E= (η/2)·mfυL2, in which υL is the limit collision velocity.
    (3) There exists the optimum frequency that makes the machining energy the maximum. Even if the machining condition may vary, it is necessary, however, to maintain the ratio of the exciting force to the frequency to be a definite value for machining at the condition of limit collision velocity.
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  • Characteristics of Apparatus
    Hiroo KATO
    1964 Volume 30 Issue 358 Pages 876-882
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    A kinetic energy of shot projected is obtained from the measurements of the number, diameter, speed, etc. of shot as an electric pulse. An apparatus is designed and consists of a condenser type converter, a microcapacity circuit, an amplifier, a pulse amplitude selector, a time signal generator, a pulse duration selector and a counting circuit. The grid voltage-plate ampere characteristics of the gated beam tube, 6 BN 6, is applied to these selectors and a time signal generator.
    When the steel ball of 1.04.0mm in diameter passes vertically between the condenser plates of the converter, the output pulse is generated. This pulse amlitude is proportional to the 3.2 th power of the diameter of the ball and the reciprocal of this pulse duration is equal to the falling velocity. A pulse amplitude selector and a pulse duration selector discriminate the pulse of higher amplitude and longer duration than the predetermined values respectively. Thus the output pulse is counted with the relative error of ±8 %.
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  • [in Japanese]
    1964 Volume 30 Issue 358 Pages 883-891
    Published: November 05, 1964
    Released on J-STAGE: October 08, 2009
    JOURNAL FREE ACCESS
    Download PDF (20870K)
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