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Volume 42 (1980 - 198･･･
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Volume 42, Issue 2
Displaying 1-18 of 18 articles from this issue
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[in Japanese]1980 Volume 42 Issue 2 Pages 197
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (223K) -
Comparison with Measured ValuesJun Sakai, Koichi Iwasaki, Koichi Hashiguchi1980 Volume 42 Issue 2 Pages 199-202
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the problems such as the bearing capacity of farm soils or the indentation resistance of rigid punches to various machine elements, the width of loaded materials is not generally wide enough to be regarded as a semi-infinite body. The bearing capacity of the infinite body in the shape of a truncated wedge subjected to a single strip load was analyzed by use of slip-line method in the previous paper. Then, the applicability of analytical solution to practical problems should be verified by experiments.
In this paper, the authors report as to the model tests carried out to verfy the applicability of the theory mentioned above. A mixed soil of sand and clay was used in the model test. The cohesion and the angle of internal friction of the soil are 0.826kg/cm2 and 14.28° respectively, while the physical properties are shown in Table 1. The measured values of bearing capacity are shown in Table 2 in which φ is a half spreading angle of the wedge and ω is a ratio of the loading width ω to the top width W of materials.
The comparisons of the theory to experimental results are shown in Fig. 5 (a), (b) and (c). These figures show that the theoretical curves approxi-mate over the whole trend of experimental values, except for the small alue of ω. The bearing capacity for the state including the wide plastic zone, i. e., for the small value of ω would be generally overestimated, because the theoretical values are calculated using the cohesion and the angle of internal friction prescribed by the maximum shear stress.
It could be concluded through these comparisons that the theory formulated by the authors provides a guiding principle to predict the bearing capacity of plastic bodies such as soils, metals and so forth in the shape of truncated wedge.View full abstractDownload PDF (2059K) -
Tilling Reaction Force Detector and Investigation of Control SystemTateshi FUJIURA, Noboru KAWAMURA, Phu Si GIA1980 Volume 42 Issue 2 Pages 203-209
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESS1) The gain of the tilling reaction force detector with torsion-bars had its peak frequency of 11Hz. However by filtering the peak frequency, the detector was suitable as the input unit of the travelling speed and tilling depth control system.
2) The tilling reaction force (F1) not involving the thrust force acting on a blade was measured. The line of action of F1 passed throuth inside the rotating circle of the blade tip, and the direction of F1 was changed with the rotation of the blade. The force F2 which is equivalent to the average value of F1 passed outside the rotating circle of the blade tip. In case of the experimental conditions, the change of the direction and the location of F2 caused by the change of the tilling pitch and depth was comparatively small. Consequently, the tilling torque could be detected accurately by the tilling reaction force detector with torsion-bars.
3) According to the digital simulation, the tilling torque fluctuation was small when the rate of the tilling depth change was set in the small range. If the rate was too great or the dead zone of the tilling reaction force was set small, the system behaved unstable.View full abstractDownload PDF (1080K) -
Model Test of tilling with Two BladesNoboru KAWAMURA, Sakae SHIBUSAWA1980 Volume 42 Issue 2 Pages 211-219
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe model tests on which soil blocks were tilled by rotary tiller with 2 blades were done to confirm the characteristics of energy, torque, horizontal and vertical forces in deeper rotary tilling, and the following results were obtained.
(1) In the case of down cut tilling, rotor radius smaller than tilling depth was favorable for deeper rotary tilling, because tilling energy was less, torque curve was smoother and reaction force was smaller and more upward in direction, hence pushing force to tractor will be smaller (Fig. 5, 6).
(2) Tilling energy of up cut tilling was less than that of down cut, and this was much more evident when the ratio of tilling depth to rotor radius was higher.
(3) In Japanes curved blade, most of tilling energy was consumed in the cutting by curved blade portion. Therefore, the form of that portion was important to design the blade of less tilling energy.
(4) When the ratio of tilling depth to rotor radius was higher than 1.4, a large quantity of soil nearby the surface fell down to the bottom and was cut again in both direction of rotation. In such a condition, the blockage of tilled soil and the increase of tilling energy will be caused in field operation. However, if the soil is thrown enough so that it is not tilled again when radius is smaller than tilling depth, tilling energy will be less.View full abstractDownload PDF (1411K) -
Haruo EZAKI, Masami UENO, Syotaro YUZAWA, Akira YODA, Michikazu ICHIKA ...1980 Volume 42 Issue 2 Pages 221-227
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the present National Test for Agricultural Machinery, only one estimation to the mechanical strength of rice seedling mats for Japanese-type rice transplanter is done by the measurement of dividing resistance to five or six rice seedlings. We reviewed that this test was the most suitable method to represent the dividing properties of rice seedling mats.
1) At first, the dividing test based on the method by pulling five or six seedlings apart from their own mat was done (cf. Fig. 1). The experimental results showed that through the test of thirty times the measurements was not able to provide an accurate dividing resistance of a mat, because the confidence interval was so large for the confidence coefficient 95% (cf. Table 3)
2) After the dividing test by use of many methods and devices were examined one method was chosen for this study, which a mat can be divided into two parts in the parallel plane to short edges of a mat by the use of an experimental instrument shown in Fig. 4. In spite of a few measurements for the mat, the confidence interval for the dividing resistance with confidence coefficient 95% became smaller than that of above-mentioned test (cf. Table 3 and 5). It can be found that this test is able to estimate more accurately the dividing resistance. The improvement of dividing test method presented in Fig. 4 would be recommended.
3) The four characteristic values to represent the dividing curves (load-displacement relationship: cf. Fig. 5), namely the dividing resistance, the dividing secant modules, the initial secant modules and the half-value width, are available to estimate the dividing properties of rice seedling mats.
4) The kinds of bed soil, the days for raising of seedling and the planting rate were regarded as parameters of factor on the dividing properties. Moreover, the weight of roots and the water content of mat seemed to be complex factors. The following trends can be observed generally to these factors. The heavier the weight of roots is, the larger the dividing resistance occurs. Mats became softened wifh the increase of their water content. The kinds of bed soil also affect the dividing properties, so the kinds of bed soil should be considered to make strong mats.View full abstractDownload PDF (1021K) -
Influence and Effective Factors on the Torque Fluctuation of Crank-shaft and the Vibrations on the Part of Transplanting MechanismShigeo UMEDA, Nobuo HONAMI, Vinh Duc CHAU1980 Volume 42 Issue 2 Pages 229-235
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe dynamic characteristics due to the motion of rice transplanting mechanism were influenced by the factors such as the backlash of driving gear, the cam acting on the pusher to insert the seedling into the soil, and the fundamental mechanism of the four bar linkage. Therefore, in this paper, the factors affecting on the dynamic characteristics of planting mechanism were discussed based on the experimental result.
The torque of crank-shaft, the angular velocity, and the acceleration on the part of planting mechanism, just above the axle of lever, were measured, and the main results obtained were as follows:
1) The measured torque fluctuation of crank-shaft showed the impulsive components due to the variations of angular acceleration mainly caused by the backlash of driving gear and the cam acting on the pusher to insert the seedling into the soil.
2) It seemed that the frequency component of 4f0 (f0: rotational frequency of crank-shaft) was dominant for the torque fluctuation, while 2f0 was dominant for that excluded the effect of cam by the frequency analysis.
3) Vibrations of acceleration on the part of planting mechanism were mainly caused by the vibration of engine transfered through the frame and the torque fluctuation. However, the effects of the latter appeared evidently on the vibrations of displacement due to the increase of revolutional speed of crank-shaft.View full abstractDownload PDF (963K) -
Model Experiments for Harvesting Mechanics with disksTadashi FURUYA1980 Volume 42 Issue 2 Pages 237-241
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a root vegetable harvester which took roots with soil around them, a primary model which was consisted of a pair of disks arranged in parallel was developed. The efficiency of the model and the kinematic locus of roots were tested by using root vegetable simulator in an artificial field.
The result of experiments showed that the taking efficiency of the model was almost same efficiency as the rectangular plates in the previous report. And it was recognized that the simulator was inclined forward or backward by the behavior of revolving disks. But this inclination was very small compared with the broken angle of roots.
From the analysis based on these results, it was considered that the harvesting mechanics with disks was simple and its efficiency was high.View full abstractDownload PDF (692K) -
Details of Unit of Automatic Sacking DeviceMasato SUZUKI, Haruo EZAKI, Sasakazu IMAZONO, Takao SUGIYAMA, Masao MA ...1980 Volume 42 Issue 2 Pages 243-249
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this paper, the functions and the mechanism employed for the automatic sacking device were discussed in detail.
Basically, the sacking mechanism consists of the following functions; hanging, dividing and releasing of the bag, weighing of the grain sacked and grain tank to store the grain during the replacement of the bag.
In designing the device, many possible functions were adapted to each mechanism so as to make it compact and simple.
In case of bag divider, which is one of the important mechanisms, functions of hanging, dividing and releasing of the bag were combined using a pair of auger or cam as shown in Fig. 4 and 5. These mechanisms are engaged for three operations during one revolution of the screw auger or the cam.
To determine the capacity of grain sacked, the small grain tank was used. The level of the grain in the tank was measured by level switch and then the grain was discharged through a rotation of shutter. Several types of grain tank were designed and tested. The grain tank with the rotating shutter as shown in Fig. 9 was the most adaptable design from the practical point of view. The capacity of grain sacked was determined by counting the number of rotation of the shutter. Thus, the functions of weighing, storing and discharging were included in the grain tank and then the chute, to guide the grain discharged from the tank to the bag and to open the grain bag, was also attached to the grain tank as shown in Fig. 12.View full abstractDownload PDF (8251K) -
A Comparison between Thermal and Moisture Stress, and an Arrangement of Rice Cracking Data on the Weibull Probability PaperShinkichi YAMAGUCHI, Shingo YAMAZAWA, Kaichiro WAKABAYASHI, Hachiro HO ...1980 Volume 42 Issue 2 Pages 251-257
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe experimental results showed that the cracking of brown rice grains was not brought about by thermal stress but by moisture stress. From an approximate calculation of internal stresses of a brown rice during the drying process, it was obvious that the thermal stress in the rice grain was negligibly small as compared with the moisture stress. In the present paper, it could be concluded that the rice cracking during the drying process was exclusively caused by the moisture stress.
By plotting the rough rice cracking data which were obtained by thin layer drying on the Weibull probability paper, the following informations were obtained. 1) Within about 4 hours of drying time, the shape parameter m became always about 1.3, and both of the scale parameter to and the location parameter γ decreased with increasing drying temperature and with decreasing initial moisture content of the rough rice. 2) After the maximum percentage of cracked rice in about 4 hours of drying time, the percentage decreased with increasing drying time.View full abstractDownload PDF (1072K) -
Kenichi ISHIBASHI, Hiroshi KOAZE, Kazunori HIRONAKA, Taisei OKAMURA1980 Volume 42 Issue 2 Pages 259-264
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe influence of absolute humidities of room air on bean moisture measurement was investigated. Discussion was made on the relationship between the observed moisture contents by vacuum-oven methods at 98±2°C as standard and air-oven method at 105°C. The experiments were carried out using about 10g of whole beans.
The results obtained from these experiments were summarized as follows.
1. Effects of atmospheric absolute humidities on measured moisture contents of soybeans were not recognized.
2. There was a good agreement between vacuum-oven method and air-oven method at 105°C for 24hr for soybeans having moisture content less than 20% (w. b.). Moisture contents of soybeans with more than 20% (w. b.), however, must be determined by air-oven method at 105°C for 48hr.
3. Although air-oven method at 105°C for 72hr was recommended both for Azuki beans and kidney beans (Gintebo and Taishokintoki, respectively), it was advisable to operate the air oven at 105°C in a room of a constant atmospheric absolute humidity to minimize deviation of measured moisture within samples.View full abstractDownload PDF (871K) -
On the Screening Ability and its affecting factorsAkira AKASE, Masanori TSUCHIYA1980 Volume 42 Issue 2 Pages 265-273
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to clarify the effects of the factors affecting the screening ability of brown rice by the rotary type screen, the authors carried out continuous operating tests with long cylinders and batch-type one with short cylinders. The main results were as follows:
(1) The screening ability of brown rice by the rotary type screen became higher with the increase of the rotating speed of the cylinder N (rpm), and it reached the maximum when N was in the range of 70 to 85rpm, then it became lower. The screening ability also became fairly higher as the feed rate of material Q (kg/min) was decreased and three agitating rods were attached to the cylinder.
(2) The weight of material per unit length of the cylinder w (kg/m) was decreased with the increase of N, and after reaching the minimum it was increased later. The value of w also was increased in the case of the cylinder with three agitating rods and was in proportion to Q.
(3) For the test with short cylinder, the passage rate factor λ1 (1/sec) was examined based upon w, the size fraction of small particles and N. The value of λi was increased with the decrease of w and the size of small particles.
(4) The flow velocity of material Vf (m/min) and the screening time T (sec) were calculated from w. The separating efficiency E (%) was calculated from Feller's equation by using the value of λi and T. Both these efficiencies and the one determined from the experiment showed almost the same values.
(5) As a result of the decrease of w according to the increase of the inclination of cylinder, T was decreased, but λi was increased. And the separating efficiency was dependent on λ1 and T.
(6) By investigating λ1 and T separately, the effects of screening factors can be evaluated easily and precisely with a little amount of material.View full abstractDownload PDF (1201K) -
Takashi TAKEZONO, Kensuke AMANO1980 Volume 42 Issue 2 Pages 275-280
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA rock-pile heat storage is a useful method for a solar air heating system. In constructing HITSUJIGAOKA solar greenhouse, large-sized round stones were used, because of their ability of high thermal exchange, weather and corrosion resistance. Also, they were useless products of land cultivation and did not require much energy to move air through the rocks. In this paper, a feature of the storage and some problems in designning the rock-pile storage were discussed, based on a whole year operation test.View full abstractDownload PDF (860K) -
Results from Suspended Solution of Cattle WasteHiroshi SHIMIZU, Junichi TAKEDA1980 Volume 42 Issue 2 Pages 281-285
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSBasic experiments of filtration were made on suspended solution of cattle waste by the Leef-test method and the result was compared with the one of swine waste. The authors obtained the following results from experiments for 60 conditions in which two types of filter medium were used as; 74μ sieve mesh with (rice hull charcoal by combination of body-feed and pre-coat) and 246μ filter without aid.
(1) Effectiveness of using rice hull charcoal as the filteration aid was recognized from the fact that the limit filtrate volume (vn) of the 74μ filter became 2.2 times as big as that of 246μ filter (Fig. 4-1 & 2). The vn for cattle slurry was almost twice as big as that for swine slurry.
(2) Elimination rate (S) was almost constant with respect to initial slurry density (Vo). Compared with swine slurry, S for cattle was 1.28 times bigger with 246μ filter and 1.33 times bigger with 74μ filter.
(3) Increase of Wo yielded a slight increase of dry weight of filter cake (Wcn) for 246μ filter without aid but showed a remarkable increase for 74μ filter with aid. The value of cattle slurry Wcn was 2.5 times as large as swine slurry.
(4) Parameter j in eq. (1-17) was almost a constant value. The mean value of j for cattle slurry was 10% bigger than that for swine slurry, which suggests that the cattle slurry cake keeps a better water-permeability than the swine slurry.
(5) Parameter k in eq. (1-17) for cattle with use of 246μ filter was 15 times and k with 74μ was 6 times as big as those for swine. Cattle cake seems to be slower in choking the filter sieve.View full abstractDownload PDF (666K) -
Yoshiaki GOTO, Kenji YAMAMOTO1980 Volume 42 Issue 2 Pages 287-292
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESS1. It is very difficult to remove the dust on the greenhouse covered with PVC film only by the rain. All growers in Japan who have PVC-greenhouses are, in fact, required to remove the covered film and put on the new one once a year or every two years. It required much labour and expenses. Dusty PVC film also weaken light-transmittance and prevent sound plant growth. An experimental PVC-greenhouse cleaning machine of water turbine type was designed and built for the test of its perfomance.
2. The cleaning machine was connected by a hose with power sprayer used for pest and disease control. The water from the sprayer gave power to the turbine and was used again as cleaing water distributed on the film surface. In order to obtain good results of cleaning, the machine was so designed that the film should be attracted to the brush rotating together with the turbine.
3. Through a number of experiments, the machine appeared satisfactory with such points given at the beginning of design as (1) performance of cleaning, (2) attractive effect to the film, (3) water distribution on the film, (4) easy handling. And it was adopted successfully for practical use among the persons concerned.
4. The cleaning machine with attractive effect to the film was patented at 7th June 1973. The experimental machine has been placed to commercial development and produced for the market.View full abstractDownload PDF (2386K) -
Yutaka Chuma, Kei Nakaji, Masanobu Ohura1980 Volume 42 Issue 2 Pages 293-299
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSFundamental characteristics of Delayed light emission (DLE) from Japanese apricots (Prunus mume SIEB, et Zucc.) were investigated to evaluate the maturity and freshness of the fruit.
1. DLE intensity of Japanese apricots increased with the times of dark periods ahead of excitation, with the exception under 1min of dark period. The highest intensity of DLE was obtained at the dark period of 20min under the decay period of 1.5sec (Fig. 1).
2. The exciting conditions for obtaining the high and stable DLE intensity were obtained as follows: (Fig. 2, 3, 4)
Exciting time; 1sec,
Illumination intensity; above 5500lx,
Fruit temperature; 23-28°C
3. DLE characteristics of Japanese apricots were measured by the dark period of 10min, exciting illuminance of 5500lx, exciting time of 2sec and decay period of 0.7sec, and the following results were obtained.
(1) DLE intensity, hardness and acid content of Japanese apricots had little changed according to the harvest date during the commercial harvest periods (Fig. 5).
(2) Harvested Japanese apricots placed in a room temperature were softened and yellow-ripened rapidly (Fig. 5). Commercial value of the apricots declined at the time the hue of peel color changed into 2.5GY, accompanied with the remarkable decrease of the DLE (Fig. 6).
(3) The DLE intensity was found to be directly proportional to the hardness of Japanese apricots (Fig. 7).
4. Four sorts of storage conditions were compard for twelve days with Japanese apricots. Low temperature storage of 10°C was effective for preserving freshness of the apricots, and the freshness of stored fruits were evaluated by means of DLE (Fig. 8, Table 1).View full abstractDownload PDF (1141K) -
[in Japanese]1980 Volume 42 Issue 2 Pages 301-304
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (523K) -
[in Japanese], [in Japanese]1980 Volume 42 Issue 2 Pages 305-308
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (834K) -
1980 Volume 42 Issue 2 Pages 309-314
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1125K)
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