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Volume 42, Issue 498
Displaying 1-13 of 13 articles from this issue
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[in Japanese], [in Japanese]1976 Volume 42 Issue 498 Pages 526-532
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1253K) -
On Accuracy of Contouring by Numerically Controlled Machine Tools (1st Report)Yoshiya FUJII, Hiroyasu IWABE1976 Volume 42 Issue 498 Pages 533-538
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper deals with the profile error of generating a circular contour by numerically controlled machine tools and presents the influence of cutting forces on profile error. The results are as follows.
(1) In machining a circular contour, feed rate changes at a period of 90° for simultaneous 2 axes controller or 45° for 1 axis. It is why feed rate depends upon pulse interpolation for a circle and reading time of a command tape.
(2) Dimensional error obviously varies with the cutting force which is increased with an increase of depth of cut or feed rate.
(3) The behaviour of dimensional and periodic error of a circular contour is shown geometrically by a model under rough cutting conditions.
(4) It is shown that the decrease of depth of cut and also of the difference of feed rate in the circumference of a workpiece improves the periodic error.View full abstractDownload PDF (945K) -
The Relation between Microstructures and Tool WearRyozo KITAGAWA, Kitao OKUSA1976 Volume 42 Issue 498 Pages 539-544
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCarbide tools for machining rolls are apt to be fractured at the cutting edge. Therefore, the carbide grades of WC-Co having low contents of TiC, TaC, Co, low transversal rupture strength and high hardness are generally used. Predominant cause of the tool wear when cutting of rolls of high hardness is considered to be falling off of carbide particles which slowed out of the tools by the hard particles exclosed to the bottom side of the chips and those to the surface machined. Therefore, the relation between the mean free path of Co-phase and grain size in microstructures of carbide tool and the tool wear is investigated, additionally including that with carbon steels and cement-mortar as materials cut. The following are found. The shorter the length of mean free path is the case of the predominant cause of wear that is the abrasion type as in the machining of rolls, and the larger the mean grain size is in the case of that of the attrition type as in the machining of carbon steel, the longer tool life is obtained respectively. And the adaptability of carbide tools for the machining of rolls can be examined simply by the machining of cement-mortar.View full abstractDownload PDF (1399K) -
Fundamental TheoryKoichi KAMEOKA1976 Volume 42 Issue 498 Pages 545-549
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe lever system is one of the most fundamental components of the mechanical lever scales. In this paper, a new vibration isolation theory is proposed of the lever system in a case where each fulcrum of the levers is fixed at the vibrating foundation. The lever system which consists of the number n of levers is analysed, and a new concept "J-Balance", which characterizes the vibration isolation, is introduced. Using this concept, the conditions of the vibration isolation, even if the vibration is random or not, can be expressed as follows; to adjust the lever system to "J-Balance", and to adjust both of the spring constant and the viscous damping coefficient of each lever except the weighing beam at zero. Under these conditions, the weighing beam vibrates in a vertical line, but stops the rotational vibration about the fulcrum. So, there is no effect of the vibration of the foundation on the weighing. This theory is based on the peculiarity of structure of the lever system and its dynamical characteristics. This paper describes a new lever system model based on the theory and discusses problems in a case when applying the theory to practical problems.View full abstractDownload PDF (708K) -
Cutting MechanismSusumu KASEI, Masahiro MASUDA1976 Volume 42 Issue 498 Pages 550-556
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSOn turning with self-propelled rotary cutting tool, the effective rake angle is approximately equal to the normal rake angle from the relative stand point of view. If the cutting mechanism is varied by the rake angle, it will be difficult to understand its variation upon cutting with rotary cutting tool. Therefore, this cutting mechanism is discussed from the absolute stand point of view and is compared with the conventional cutting. The results obtained are as follows.
(1) The angle of chip flow plays only a part which varies the tool-chip contact length.
(2) The self-propelled rotary cutting tool is equivalent to the tool with restricted tool-chip contact length in cutting mechanism.View full abstractDownload PDF (1060K) -
On Cutting with Internally Cooled Cutting Tool (3rd Report)Sadaji OKAMOTO, Masahiro DOI1976 Volume 42 Issue 498 Pages 557-561
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper describes the theoretical and experimental investigations for the relationship between the quantity of diffusion and the cutting temperature for clarifying the cooling effect on crater wear. The main results obtained are as follows:
(1) The diffusion of Fe contained in work material into Co phase of tool material is found by experiment. The effect of cutting temperature on diffusion of Fe appears clearly.
(2) The value of theoretical crater wear agrees approximately with that of actual crater wear. The relationship between crater wear K and temperature T can be expressed by the following equation.
log K=-3.5/T × 103+B;where, B theoretical value ; 5. 0 experimental value; 4. 7
Then the crater wear due to the cooling effect can be calculated quantitatively on the basis of a reduction of cutting temperature T.View full abstractDownload PDF (1064K) -
Masataka YOSHIMURA, Kazuo URAKAWA1976 Volume 42 Issue 498 Pages 562-567
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn order to obtain the vibratory characteristics and quantitative values of the rigidity and damping at the bolted joint which is one of the representative joints in the machine structure, the experimental measurement was performed of a free-free beam containing a bolted joint which was excited at resonances together with the theoretical simulation of the beam by the computer program system. Recognizing that the pattern and the magnitude of the force applied to the joint are the most important factors in the analysis of the characteristics at the joint, two fundamental patterns of the applied forces were realized by using two characteristic eigenvalue modes of the model, in which the moment of forces normal to the interface and the shear forces occur exclusively at respective, test frequencies. Test results were processed to result in accurate measurements by drawing the vector loci of the frequency response. It was understood that substantial damping occurred at the pattern where the moment of the force was applied. In these measurements the damping at the joint surface was dominant over those from other sources in the model. On the other hand, at the pattern where the shearing force was applied parallel to the joint surface, damping due to the interface was not appreciable. The method to gain the quantitative values of the rigidity and damping coefficients at the joint itself by interactive use of the theoretical simulation and experiment was developed and the values at this model were identified.View full abstractDownload PDF (1201K) -
Jiro ISHIKAWA, Yuichi ISHIKAWA1976 Volume 42 Issue 498 Pages 568-572
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe system of accuracy for cylindrical gears has been defined in JIS B 1752 and ISO 1328, and the accuracy of gears has been expressed in terms of individual errors such as the pitch error, the tooth profile error, the eccentricity, etc. Each of these methods, however, is not satisfactory to express the accuracy of gears such as the angular transmission error and tooth bearing error. A new gear accuracy measuring system with micro-computer is proposed. Many points on the tooth profile of gears are measured according to the three coordinate systems, and the micro-computer calculates the tooth error by comparing the results with the theoretical values. By illustrating the tooth errors around the gear teeth with the arc of base circle, the accuracy of gear is more adequately expressed than by any of the conventional methods.View full abstractDownload PDF (993K) -
Yoshio IMAMURA, Sennosuke SATO, Mitsuo KUROHA1976 Volume 42 Issue 498 Pages 573-578
Published: June 05, 1976
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSDynamic stress or strain distribution in a spur gear were measured in gear teeth gearing by means of the copper electroplating method. The experimental results were compared with some practical design formulas on the nominal stress of gear tooth. The following conclusions were obtained:
(1) The maximum tensile stress and compressive stress in the root of tooth surface are larger about 20% than those of the side surface.
(2) The stresses of compression side in the root of gear tooth are larger about 10% than the tension side.
(3) The bending stresses in the root of gear tooth in the tension side agree fairly with those calculated by the design formula of Japan Society of Mechanical Engineers.
(4) The position to occur the maximum stress in the root of gear tooth was found to approach to the root, and was defined as the point where the straight line through the worst loading point contacts tangentially with the fillet curve of gear root.View full abstractDownload PDF (1587K) -
Akira YAMAMOTO, Yoshiaki MAEDA1976 Volume 42 Issue 498 Pages 579-585
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn recent years, vibrations of the machine-tool systems have been investigated by many researchers and so many available knowledges have been given. But, about torsional vibrations, only a little investigation has been carried out from luck of the appropriate measuring method. So, for the further experimental analysis of this field, a new measuring method has been developed by the utilization of a marketing wow-flutter meter usually used for the audio recording and reproducing apparatuses. In this paper, the principle and the basic characteristics of this method are discussed and an example of the application, the measurement of the arbor speed variation of the typical small horizontal milling machine, is shown. Main results are as follows:
(1) The developed method not only has a better high frequency response (280 Hz: -3 dB) in comparison with hitherto reported ones but also can make the measurement comparatively easy and measure even small variations below 0. 1% p-p of mean speeds with a good accuracy.
(2) The application shows that even in the racing condition the arbor speed of the tested machine variates with the maximum amplitude of 0.2-0. 3%p-p of the mean speed and the dominant frequency components of this variation mostly result from (a) the fluttering of V-belts between the drive motor and the gearbox, (b) the eccentricity of the arbor, (c) the torsional resonance of the driving system and (d) the gear-noises rising in the gearbox. These aspects may be generally applicable to other machines too.View full abstractDownload PDF (1441K) -
[in Japanese]1976 Volume 42 Issue 498 Pages 586-592
Published: June 05, 1976
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDownload PDF (1192K) -
[in Japanese]1976 Volume 42 Issue 498 Pages 593-597
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (957K) -
[in Japanese]1976 Volume 42 Issue 498 Pages 598-600
Published: June 05, 1976
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (468K)
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