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Volume 51, Issue 3
Displaying 1-20 of 20 articles from this issue
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1989 Volume 51 Issue 3 Pages 1
Published: 1989
Released on J-STAGE: April 30, 2010
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1989 Volume 51 Issue 3 Pages 2
Published: 1989
Released on J-STAGE: April 30, 2010
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Toshiaki ASHIZAWA1989 Volume 51 Issue 3 Pages 3-4
Published: 1989
Released on J-STAGE: April 30, 2010
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Ultrasonic Atomization of Alcohol and Preheating of Intake AirHideo TERAO, Kazuhiko OHMIYA, Noboru NOGUCHI1989 Volume 51 Issue 3 Pages 5-13
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper describes the effects of alcohol atomization and preheating of intake air on the improvement in engine performance and the the reduction of exhaust gas emissions. Two kinds of atomization apparatus with a ultrasonic transducer were devised. One was called “impulse method”, which had the characteristic resonant frequency of 29.3kHz, the other was “ultrasonic method”, which had that of 1.5MHz. In accordance with the preliminaly experiment using steady air flow through the model intake tube, it was found that the impulse method generated a fine mist of uniformly sized alcohol droplets into the intake tube, and the ultrasonic method excessively promoted vaporization due to minimized droplets. In the engine tests, it was clear that the impulse method was available to improve engine performace and reduce exhaust gas emissions. Under the higher loads, it was also necessary to increase intake temperature up to 70°C. When these conditions were fulfilled, the obtained effects were as follows. Under moderate loads, BSHC was reduced by 5% and as for exhaust emissions, HCHO was by 30% and UBM by 35%. Under the higher loads, both of HCHO and UBM could be reduced by 30% without the increase in BSHC.View full abstractDownload PDF (3712K) -
Masanori KITANO, Keiji WATANABE, Osamu AKIMOTO, Kazue TOGO1989 Volume 51 Issue 3 Pages 15-22
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper describes the prediction method of a track slip and sinkage of tracked vehicles under steering motion on level soft ground. The basic factors such as a sinkage, tractive force and bulldozing resistance as a friction of slippage and ground contact pressure were taken into account to develop the mathematical model of the transient turning motion. Especially, Anisotoropic characteristics between the track slip direction and track sinkage and frictional forces have been disclosed.
As the results, it is found that the model is useful for the evaluation of track sinkage and mobility.View full abstractDownload PDF (5810K) -
Lateral Forces of Driven or Braked TiresShu-huai ZHANG, Hideo TERAO1989 Volume 51 Issue 3 Pages 23-31
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTo predict lateral forces of driven or braked tires, a simple dynamic model of tire-ground interactions was proposed. And for investigating the adequacy of the tire dynamic model, verification tests were also carried out.
The conclusions were as follows: (1) As slip on the tire centre plane dimension was within the extent of -40%-40%, that is, |sx|<40%, simulation results from the tire dynamic model were in agreement with the verification test results in general. (2) When the tire slip angles became larger, the driving or braking force coefficients became smaller. However, the lateral force coefficients became larger. And the lateral force coefficients decreased as the driving or braking force coefficients increased. (3) The relationships between the tire slip angles and the lateral force coefficients were found to be unlinear. When the tire slip angles were less than 5°, the variation of the lateral force coefficients was larger relatively.View full abstractDownload PDF (1129K) -
Dynamic Behaviour of a Lugged WheelX. L. Wang, T. TANAKA, M. YAMAZAKI1989 Volume 51 Issue 3 Pages 33-40
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSLugged wheels have been widely used in Southeast Asia for traction in paddy fields. In the past, many experiments in laboratory with soil bins were done to analyze soil-lugged wheel interaction mainly based on constant slip and sinkage condition. To investigate the main factors involved, an experimental device for a model lugged wheel was constructed which enabled to measure variables under actual conditions. Experiments were conducted to study slip, sinkage and reaction forces acting on a lug surface under conditions of 2 levels of vertical axial load and 3 levels of drawbar load. According to the experimental results, it was found that slip and sinkage of lugged wheel varied periodically with angle of rotation which is equal to the angle of adjacent lug. It resulted in the change of locus of a lug in soil and axle of a lugged wheel. The reaction forces from the soil to a lug was assumed to change with rotation angle of the lugged wheel at the different sinkages and slips.View full abstractDownload PDF (1236K) -
Basic Motion Equations of the LugJun SAKAI, Takaaki MATSUO, Eiji INOUE, Shigeki INABA1989 Volume 51 Issue 3 Pages 41-48
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe motion characteristics of a lug of rubber crawlers for a combine harvester were simulated by several equations to express motion loci of a lug.
In this paper, the travelling mechanism of the crawler was divided into six portions, and several equations were set up to express motion loci for a rubber crawler from driving wheel to the first track roller.
We defined four surfaces to compose the lug shape consisted of five points, and simulated the penetrative behavor of a lug into the changing parameters as inclinative angle of the front crawler and slippage.
The results of lug simulation were shown in Fig. 4.
The basic equations to discuss the motion resistance, driving forces and buoyancy of a crawler machine were obtained.View full abstractDownload PDF (1117K) -
Power Requirement and Side Force StudyMokoto HOKI1989 Volume 51 Issue 3 Pages 49-55
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSQuantitative evaluation of tilling characteristics of a PTO driven disk tiller was made by investigating power requirement and specific work under varying ground speeds of the tractor. It was found in the field tests that in comparison with rotary tiller, the energy efficiency of the PTO driven disk tiller was higher especially for high tractor ground speed. The side force acting on a disk blade was successfully measured to find the relationship to the tractor ground speed. Also the soil reaction acting horizontally to the rear wheel was measured to find that the rear wheel was functioning to provide horizontal force which counteract the side force acting to the disk tiller from the soil being inverted.View full abstractDownload PDF (3417K) -
Tokumi FUJIKI, Takayuki KOJIMA, Takaaki MATSUO1989 Volume 51 Issue 3 Pages 57-64
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe maximum velocity of air stream in a straight tube exists at the cross-sectional center of the tube. A boom type blow head, however, has outlets at regular intervals on the bottom line of the tube. Accordingly, the maximum velocity Vmax is not at the cross-sectional center and is slightly biased toward the bottom line on which the outlets are.
The authors showed experimental formula of velocity distribution to calculate mean velocity V and flux Q from the data of dynamic pressure Pd at the cross-sectional center. The velocity u of an arbitrary point on the central vertical line in the cross-section were expressed as a function of distance between the point and the bottom line as follows;
u/Vc×100(%)=αyε(1-y)ι
where:
Vc=the velocity at the cross-sectional center
y=distance from the bottom line
ε, ι=index number which express the inclination of curvature of velocity distribution
Because the horizontal distribution of the velocity is thought to be symmetry, index ε′ should be equal to ι′. And y is distance from the inner side surface. In a boom type blow head, the central velocity Vc is not equal to the maximum velocity Vmax. And the pipe factor F of the heads was found to be 0.87 in practical conditions.View full abstractDownload PDF (1051K) -
Masayuki KASAHARA, Akinari INOHARA1989 Volume 51 Issue 3 Pages 65-74
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIt is necessary to establish the rational drying method that takes the moisture contents of a single rice grain into consideration. The changes in the distribution on individual moisture contents of rough rice dried in a circuration type dryer were reported in the previous paper. In the present report, in order to develop the uniform moisture content of individual grains, a drying of rough rice in a circulation type dryer was paused for a time was adopted. And the effects of the pause during drying on the quality of rice, particularly the cracking of rice kernels were investigated. The results showed that the short pause of drying decreased the unevenness of moisture content of individual rough rice kernels and reduced the cracking drying. And the pause of drying elevated the measuring accuracy of moisture during drying and reduced the decrement of moisture contents of brown rices after drying.View full abstractDownload PDF (1553K) -
Satoshi MURATA, Akio TAGAWA, Toshio KAWANO, Sadato ISHIBASHII1989 Volume 51 Issue 3 Pages 75-80
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe chipps of several kinds of cereals (brown rice, wheat, barley, and wheat starch) were analyzed by DTA to determine the upper limit temperature for drying. From the analysis, the denaturation temperatures were determined to be 53.3°C, 55.1°C, 54.4°C and 51.0°C, respectively, The peak temperatures at which the most vigorous reaction occurred with increasing heating rate were analyzed by Kissinger's formula of chemical kinetics.View full abstractDownload PDF (849K) -
Clarification of Production Mechanism of Fine Air BubblesJinzo NAGAHIRO, Junjiro IWAMOTO, Ken HIGUCHI1989 Volume 51 Issue 3 Pages 81-87
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSEjector type gas-nozzle produces fine air bubbles in a very limited space of the parallel part in the gas nozzle. Thus, by visualizing the liquid jet and the aspirated air jet in the parallel part of the gas nozzle, the mechanism of the production of fine air bubbles was clarified experimentally. As a result, it was known that the fine air bubbles were produced in the following way: the air was aspirated in the form of wedge shape into the space between the liquid jet in the gas nozzle and the liquid layer remained on the nozzle wall due to the viscous force exerted between the surface of the liquid jet and the air. Fine air bubbles were, then, produced under the shearing action which was brought about by the relative motion of the liquid jet and air flow at the downstream end of the air jet, or at the point of contact between the liquid jet and the liquid layer on the nozzle wall.View full abstractDownload PDF (3441K) -
Yasumasa KOGA1989 Volume 51 Issue 3 Pages 89-95
Published: 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn regard to the social implications of improving postharvest processing technology, the reduction of postharvest loss and the resultant additional food supply have often been emphasized. However, such tecnhology composes a part of overall postharvest processes and marketing executed by several social strata, which are strongly confined with various social circumstances, without clarifying the specific nature of postharvest processes and marketing in the society, it would be difficult to reach the target.
Further, it is questionable whether postharvest technology can be developed with such motivation as above. and it is doubtful whether the most important implications of postharvest technology improvement are on such points.
It is envisaged that there is strong influence on the economic and cultural development both of society and of farmers themselves, specifically when farmers undertake postharvest activities extensively. Farmers may be able to develop their technical skill and cooperation among them through these. It can also contribute for the modernization of the society.View full abstractDownload PDF (1313K) -
Kimyung LEE, Osamu KITANI, Tsuguo OKAMOTO1989 Volume 51 Issue 3 Pages 97-100
Published: 1989
Released on J-STAGE: April 30, 2010
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Rotary Head TypeYasuhiko MIYAKE, Katsuyuki MANZAWA1989 Volume 51 Issue 3 Pages 101-106
Published: 1989
Released on J-STAGE: April 30, 2010
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[in Japanese]1989 Volume 51 Issue 3 Pages 107-110
Published: 1989
Released on J-STAGE: April 30, 2010
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[in Japanese]1989 Volume 51 Issue 3 Pages 111-114
Published: 1989
Released on J-STAGE: April 30, 2010
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Testing know-hows for soil binsJun SAKAI1989 Volume 51 Issue 3 Pages 115-118
Published: 1989
Released on J-STAGE: April 30, 2010
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[in Japanese]1989 Volume 51 Issue 3 Pages 119-122
Published: 1989
Released on J-STAGE: April 30, 2010
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