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Volume 42 (1980 - 198･･･
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Volume 42, Issue 3
Displaying 1-20 of 20 articles from this issue
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[in Japanese]1980 Volume 42 Issue 3 Pages 327-328
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (326K) -
Masami UENO, Haruo EZAKI, Koichi HASHIGUCHI, Jun SAKAI1980 Volume 42 Issue 3 Pages 329-334
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a first step to apply a finite element method to the analysis of soil resistance problems in the field of agricultural machinery, an explicit boundary value problem was analyzed by the finite element method adopting the stiffness equation deduced from the constitutive equation taking account of the elastic-plastic transition, and the validity of this analysis was examined as follows.
1) A load-settlement problem, one of the most fundamental boundary-value problems, was adopted as an explicit problem. The settlement test of a rigid strip footing on the sand bed was first carried out as shown in Fig. 2. The load-settlement curve obtained from this test is shown by the solid line in Fig. 3.
2) The load-settlement problem under the same condition as the above-mentioned test was analyzed by the finite element method. The calculated load-settlement curve is shown by the dashed line in Fig. 3. Further, the deformed configuration, the state of principal stresses, the isobars of vertical stress and the plastic zone at the 10.5mm settlement are depicted in Figs. 5, 6, 7 and 8 respectively.
In Fig. 3 we see the good agreement between the experimental load-settlement curve and the theoretical one.
The finite element method introduced in this paper would provide the useful theoretical guide to the estimation of the deformation resistance of real soils.View full abstractDownload PDF (981K) -
Relation between produced pressure and physical properties of soilKenji ARAYA1980 Volume 42 Issue 3 Pages 335-345
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe object of this experiment is to develop a sub-soiler which injects fluid under pressure in order to break down soil. In this paper, when air among fluid is caused to flow under pressure into a soil-bed layer which is spread infinitely as in a general field, the extent of pressure which was raised at the nozzle port was observed in relation to the physical properties of soil (i. e. porosity, degree of saturation and specific surface etc.). The results of this experiment were as follows;
1. When the general fluid flows out of the nozzle port in the soil-bed layer in three dimensional directions, the degree of resisting pressure produced at the nozzle port is indicated by eq. (44)-in liquid or by eq. (45)-in gas. These results indicate the fundamental relations between the physical properties of soil and the resulting resisting pressure.
2. The cofficient of turbulent flow Λ and the potential constant J in the formulae (44) and (45), both of which were nondimensional, were decided through this experiment. Consequently, the extent of the resisting pressure produced at the nozzle port can be estimated, if the physical properties of soil are known. (eqs. (49) and (50))
3. As the flow rate of air was increased, the produced pressure at the nozzle port generally showed such a change as a cubic function after plotting on logarithmic graph which is shown in Fig. 4. At a certain flow rate, a cavity was generally produced around the nozzle port in the ground. With a larger flow rate, cracks appeared on the surface of the ground.
4. The size of nozzle was inversely proportional to the degree of force of the produced pressure at the nozzle port. However, in this experiment in which the soil-bed layer was 30cm in height, the flow rate which produced large cracks on the surface of the ground was around 13g/s when air flowed in.
5. The nozzle size r which is equivalent to the cavity size indicates the progress of breaking-down in the ground. It had no relation with the hardness of ground. It was chiefly influenced by the type of soil, the moisture ratio in the soil and the height of soil-bed layer.
The writer wishes to express his gratitude to the Hokkaido University Computer Center for allowing him the use of their facilities.View full abstractDownload PDF (3479K) -
Seed Detector for Planter by PhotometryYoshiichi OKADA, Katsumi ISHIKAWA, Masateru NAGATA1980 Volume 42 Issue 3 Pages 347-353
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAn error in spacing occurs with seeder when a seed or a group of seeds becomes wedged in the seeding mechanism and passes beyond the correct position for ejection during dropping.
In order to control errors in sowing which subsequently appear as either blanks or groups of seeding close together and to sow individual seeds accurately at predetermined place, seed detector using photometry was designed and examined.
1. Seed detector was constructed of 4-channel seed counter and 1 channel trouble detector. Abnormal seed detector was operated to be successful and the accuracy of counting was better than 98% for some conditions of seeds tested.
2. Counting errors were found to be caused by shorter interval between seeds, therefore, the minimum distance between one seed and the next should be as small as the slit width. Seeds bounced between the funnel and the slit, especially, the smaller seeds of any particular sample could result in double counts, the elliptic seeds being missed.
3. Seed detector was found capable of detecting errors in sowing, and this equipment should also prove valuable for development of a precise metering device.View full abstractDownload PDF (1014K) -
A New Type of Root Vegetable HarvesterTadashi FURUYA1980 Volume 42 Issue 3 Pages 355-361
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a root vegetable harvester for picking up roots with soil around them, a simple harvester which was consisted of a pair of disks arranged in parallel was developed. The harvesting performance for radishes and the adaptability to the six kinds of root vegetables which were various in the shape of main root were tested by mounting the harvester on a mid-mount type tractor.
As the results of experiments on the harvesting performance, it was recognized that the damages of radishes were not considerable and the harvesting efficiency was satisfactory. On the adaptability to the shape of main root, it was clarified that the harvester was adaptable to the various shapes of root, from the globular roots such as turnips to the cone roots such as long radishes.
From those results, it was expected that this harvester was useful for Japanese vegetable growers managing normal scale of farms.View full abstractDownload PDF (2709K) -
Kazuo KOJIMA1980 Volume 42 Issue 3 Pages 363-368
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA riding type battery car was built for transporting in horticultural greenhouses and in various agricultural facilities. The mechanism and performance of this car were summarized as follows:
1. The car was equipped with a D. C. motor as the prime mover. The voltage and output of the motor was 12V and 250W respectively. The car had four speeds forward and two speeds backward, the travel speeds varied from 0.15 to 0.7m/s.
2. Maximum input of the motor was about 180W on the earth road when loaded 126kg (maximum load) at the speed of 0.5m/s.
3. The overall efficiency on input basis of the car was 44% at maximum on the earth road.
4. Continuous operation hours of the car were about 3 hours when loaded 21kg and travel speed was the top, and the total running distance was 7, 000m.
5. As a result of simulation of harvesting and transporting with the model planting device, the work efficiency was higher for the customary working with the hand-basket than for the car, but the accuracy of picking for the car was better than for the hand-basket.View full abstractDownload PDF (4750K) -
Evaluation of Power-spectrum density of Vibrating Acceleration Affecting the In-transit Mechanical InjuryMutsuo IWAMOTO, Sumio KAWANO, Akira HAYAKAWA1980 Volume 42 Issue 3 Pages 369-374
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe effect of frequency band of in-transit vibrating acceleration on the mechanical injury was discussed for strawberries. The paper also described the method of simulated transportation test for an actual transportation which consisted of two narrow band vibrations in power spectrum density. The results were obtained as follows:
1. Mechanical injury was affected by vibrating frequency. Under the same magnitude of vibrating acceleration, the lower the frequency was, the sooner the injury came out. (Fig. 2)
2. When the acceleration was below 1.2G, mechanical injury was concentrated on the contacting parts like the fruit to fruit or the fruit to tray. On the other hand, when the acceleration was over 1.4G and the frequency was below 10Hz, the injury was distributed evenly over the whole surface of fruit. However, the injury was concentrated again on the contacting parts when the frequency was coming over 15Hz.
3. Bruise energy which was given to the fruit until the marketability was lost was proportional to (ωX2)1.36. Where ω is an angular velocity and X is an amplitude of vibrating acceleration. (Fig. 3)
4. When the magnitude of acceleration was same, repetition number of vibration which could be allowed the fruit to lose the marketability was proportional to (ω2/ω1)2.42. Where ω1 and ω2 are angular velocities of vibrating acceleration (Fig. 4)
5. The method to determine the equivalent acceleration for simulated transport test was calculated in case that the actual transporting vibration consisted of two narrow bands in power spectrum density of vibrating acceleration. (Tab. 1)View full abstractDownload PDF (906K) -
Cutting EnergyToshitake ARAMAKI, Takemi ABE, Jun YAMASHITA1980 Volume 42 Issue 3 Pages 375-382
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA dynamometer was designed to measure the two-cutting force components acting on a Goldenrod stem. Observations of the behaviour of piano-wires during cutting were carried out by high speed motion picture films. Studies were also carried out to determine the cutting torque requirement for Clover, Italian ryegrass and Goldenrod stems in the fields.
The following conclusions could be drawn through the analysis of investigation.
1. Energy for cutting a stem was directly proportional to cross sectional area.
2. A new cut-away blade cut clean as compared with piano-wire blades, but its cutting energy increased as the blade wore. Its ultimate cutting energy was more than that of piano-wire blades.
3. A knife approach angle of 0° was observed to be minimum value of cutting energy.
4. The cutting energy of cut-away blade were observed to be minimum at about 25° bevel angle.
5. The studies on the effect of knife velocity indicated that cutting energy decreased as the rate of knife speed increased.
6. The high speed motion picture films clearly showed that the piano-wire fell into disorder, and was not easy to be restored when using fine wires at low speed of blade rotation and high ground speed.View full abstractDownload PDF (3310K) -
Hiroshi SHIMIZU, Toshinori KIMURA1980 Volume 42 Issue 3 Pages 383-389
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis investigation was carried out to measure the properties of volatile matter during thermo-cracking process of rice hull. The results of this paper were as follows.
(1) The volatile matter was classified into three phases, gas, liquid and solid at room temperature. Fig. 2 showed the result in which rice hull was heated from room temperature to 600°C. step by step. The values of the mass ratio were gotten as to each phases. Amounts of the contents which organized the liquid phase and the solid phase were seemed to be comparatively large.
(2) Fig. 6 and 7 showed the results in case that rice hull was seated rapidly from room temperature to 350°C. and 600°C. Amount of volatile matter by rapid heating was larger than amount by step heating. The cracking process of rice hull seemed to be more proceeded in the former condition.
(3) Fig. 6 and 7 showed that gas phase was much in high temperature and rapid heating conditions. Cracking process of volatile matter seemed to be more proceeded under the conditions.
(4) The results of gas analysis showed in Fig. 4 through 7 that there were contained much CO2, O2 and CO in the volatile gas. Their amounts were increased under the rapid heating conditions of high temperature.
(5) Hydrocarbon and phenol compounds of high molecular were contained in other contents of the gas phase and the liquid phase. There might be higher molecular compounds in the solid phase. Under the rapid heating conditions of high temperature, the compounds were resolved into lower molecular compounds. As a result, amount of the compounds was decreased.
(6) Thermo-cracking process of organic compounds which organized rice hull was influenced by the heating conditions which related to the heating temperature and heating time. The compositions of the cracked matters seemed to change from more complex form into more simple form, which consisted of the elements shown in Table 4 and 5. The actual condition of thermo-cracked matter was understood as to the practical heating conditions.View full abstractDownload PDF (1071K) -
On the Husking CharacteristicsMasanori TSUCHIYA, Junichi KAMIDE, Akira AKASE1980 Volume 42 Issue 3 Pages 391-396
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe authors carried out the test on an impeller type rice husker which had two impellers, namely the first one and the second one, and a cleaning fan. Further the husking performance of the first impeller was investigated in both cases, being driven with and without its casing.
The impellers used in this test were a commercial one and five modified ones. The rough rice grains were cleaned by a small winnower before the test.
The main results were as follows:
1. At the revolving speed of impeller above 1550rpm, the husked ratio of the huskers having two impellers (normal machine) and only the first one were more than 99% and more than 97%, respectively. Therefore it was found that the husking action by the second impeller was small.
2. The husked ratio was scarcely influenced by the feed rate of rough rice in the range of 11.5 to 17.7kg/min.
3. The crashed kernels increased in proportion to the revolving speed of impeller, and the rate of crashed rice by the husker having only the first impeller was about 1% smaller than the husker having two impellers.
4. The required power of the husker increased exponentially with the revolving speed of impeller. The maximum husking rate was about 960kg/h on the base of rice weight, however it was possible for the rate to be increased to about 2, 000kg/h in the case where the mixture of about 1% unhusked rice mattered little. The husking efficiency was 350-430kg/ps·h.
5. From the comparative test of six kinds of the first impeller with its casing, it was found that the husked ratio of B impeller was the lowest, which had the largest curvature of the end of blade.
6. From the test of the first impeller driven without its casing, it was recognized that about 40% of the grain fed were husked during their passing between the blades of an impeller and about a half of the rest was subjected to various damage on the hulls. The husking action of B impeller was the largest and C impeller the smallest in this test.
7. The husked ratio of A1 impeller was the largest, which had a half of blades of A one. Though the reason was not clarified, this fact suggested one of the significant improvements of this husker.
8. From the test examining the course of grains between the blades of an impeller, it was found that the grains moved only on the front surface of a blade.View full abstractDownload PDF (4172K) -
On the Changes of Cracked Rice Percentage during Drying, Moisture Adsorption and Preserving ProcessesShinkichi YAMAGUCHI, Shingo YAMAZAWA, Kaichiro WAKABAYASHI, Keizo HORI ...1980 Volume 42 Issue 3 Pages 397-402
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to investigate the stress cracking of brown and rough rice grains, the change of percentage of cracked rice with the time was measured in the drying, moisture adsorption and preserving processes. Some experimental results obtained were summarized as follows:
(1) It could be noticed that the stress cracking by the drying and the moisture adsorption was caused near the center of rice kernels.
(2) In the drying processes of brown and rough rice grains, the percentage increased monotonously with the drying time after about 3 hours and reached an equilibrium percentage in about 15 hours.
(3) In the preserving processes of rice grains in an airtight container at room temperature after a given drying-period τ[hr], the percentage of cracked rice increased with the preserving time again and reached a final percentage in about 10 hours. The final percentage increased with the drying-period τ and reached a maximum value at τ≅3 for brown rice and at τ≅4 for rough rice. After the maximum percentage, the final percentage decreased with increasing τ.
(4) In the moisture adsorption process of brown rice grains, the percentage of cracked rice increased with the adsorption time and reached a maximum percentage in about 2 hours.
(5) In the preserving process of brown rice grains in an airtight container at room temperature after a given adsorption-period τ, it was observed that the percentage of cracked rice almost did not increase. It seemed that the stress cracking became light with the time.View full abstractDownload PDF (2756K) -
Sadato ISHIBASHI, Shunichiro TANAKA, Yoshiro NISHITOMI, Toshiyo MUROYA1980 Volume 42 Issue 3 Pages 403-412
Published: 1980
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe force-deformation behavior of agricultural products depends on the time scale observed.
The purpose of this paper was to illustrate the force-deformation behavior of potato specimens over a long time combining dynamic and static mechanical properties.
The summary of results were shown below.
1) The principles of linear viscoelasticity can be applied to illustrate the force-deformation behavior of potato specimens.
2) The force-deformation behavior of potato specimens was equivalent to a four-elements mechanical model. In addition, the model constants of each element were determined (Fig. 10, Table 1).
3) The relaxation spectrum of potato specimens in a logarithmic time (-4.1≤log≤3.5) was determined (Fig. 16).View full abstractDownload PDF (2591K) -
Shunichiro TANAKA, Sadato ISHIBASHI, Katsumitsu HARUGUCHI1980 Volume 42 Issue 3 Pages 413-420
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe melting phenomena of an ice sphere placed in the vacuum cooler (total pressure: 11-19 Torr, fraction of air in vapor-air mixture: 0.3-0.7) was theoretically and experimentally investigated by measuring the velocity of fusion and the vapor partial pressure of water when total pressure and electric power supply were varied.
The summary of results were shown below.
1) Condensation flux (flux of condensing water vapor) decreased with total presture (Fig. 4).
2) Condensation flux decreased with the fraction of air in vapor-air mixture (Fig. 4).
3) The linear relationship was established between logarithmic partial pressure ratio of vapor-air mixture and condensation flux (Fig. 5). Consequently, the melting phenomena of an ice sphere can be explained well by film theory within the limits of this experiment.
4) Within the limits of this experiment, the relationship between mass transfer coefficient, kx and total pressure, II, was correlated as follows (Fig. 6).
kx=22.6II-1.1View full abstractDownload PDF (1181K) -
Kentaro MOHRI, Shigeo UMEDA, Kazuhiro MATSUI, Shinroku MORITA, Toshio ...1980 Volume 42 Issue 3 Pages 421-426
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe requirement for a warm air duct used as an air heating system in a vinyl greenhouse is uniformity on temperature distribution.
The perforated heating duct was designed to uniform temperature distribution in a heating greenhouse.
A calculating method to determine the diameter of hole required for a duct to give uniform heat output per unit length, was described in this report.
The perforated heating duct was designed for 10m×40.5m single-span vinyl greenhouse. The temperatures were measured using the thermocouple at 50 points in the greenhouse, and the temperature distributions were compared with the perforated heating duct and the non-perforated heating duct.
It was found from the results of heating tests with ducted heating system, that the heating systems with the perforated duct were able to produce more uniform temperature distribution than the heating system with the non-perforated duct.View full abstractDownload PDF (918K) -
Yoshiaki GOTO, Kenji YAMAMOTO1980 Volume 42 Issue 3 Pages 427-433
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA portable PVC greenhouse cleaner was developed, which had a water turbine with disk brush and was connected to a power sprayer. It was tested in many cases to prove its performance, characteristic of the turbine, effect to the plants and so on. The results are as follows.
(1) In case of using 2.2mm caliber nozzle, the maximum efficiency of the turbine was 40.9% and output and torque were 49.7 watt and 0.0236kg-m respectively.
(2) At least 0.0150kg-m of torque was required to keep revolving the turbine. In case of 1.6mm caliber nozzle, required pressure was 13.0kg/cm2 at the point of nozzle to expect favourable result. In that case, required water for washing was saved as much as 100l/h comparing the case of 2.2mm caliber nozzle was used.
(3) Some experimental brushes were made and compared with each other in respect of durability, frictional resistance, handling, cleaning performance and others. After that it was confirmed that a brush of animal hair was more suitable for the machine than the Polyurethane foam brush in every respects.
(4) The machine was tested with two PVC greenhouses owned by private farmers which has different light transmittance of 62%, 47%, respectively. The light transmittance after washing by the machine were recovered up to 79% for both PVC houses. So it was proved to save considerable cleaning performance as compared with the new film of 83%.
(5) The influence of film washing to the plant growth were investigated. In case of eggplant, the total yields under washing was 23% higher than the non-washing.
(6) The capacities of cleaning machine was about 90-150m2/h, more than 2 times as much as maunal method by hand brush.
(7) The experimental machine has been improved, particularly on the brush part, by the users' suggestions. It is now commercially manufactured by an agricultural equipment company.View full abstractDownload PDF (4880K) -
Properties of producers, distributors and consumers on criterion of judgments for gradingKouichi AKIMOTO, Suketoshi KURODA1980 Volume 42 Issue 3 Pages 435-441
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIt is said that gradings of fruits and vegetables are mainly sorted by judgments of the appearances and the accuracies of the gradings are not so high. In this paper, therefore, the properties of the judgments for grading of Kaki (Diospyros Kaki L. cv. Fuyu) were investigated on the sorting persons in the six main producing districts, the brokers and the auctioneers in the biggest wholesale market in Japan and consumers. The results were follows:
1. The grade judgments differed among the individuals, and everybody had the fluctuation of judgment. That seemed to be due to the judgment by the sense, and to be the cause that present gradings had little reproducibility.
2. Weights for factors making the grading judgments by the sorting persons in every district, the brokers, the auctioneers and consumers were characteristics of the groups. That seemed the cause of the differences among the producing districts and individuals.
3. Weighing for factors was almost the same between the group of the sorting persons of the district shipping fruits of the highest price and the group of brokers having a great influence on the knockdown price.
4. Consumers had the severest critical values of every factors calculated by discriminant functions. The values of a surface color for the first grade, as expressed in a/b by Hunter's color system, were 0.53 by consumers, 0.32 by brokers, 0.28 by auctioneers and 0.30-0.38 by sorting persons.
5. The factor analysis on the sorting of fruits by discriminant analysis seemed to be useful for improvement on the method of the sorting.View full abstractDownload PDF (1302K) -
Suspension with Electro-Hydraulic Servo-mechanismNoboru KAWAMURA, Akira SASAO1980 Volume 42 Issue 3 Pages 443-449
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAn active-seat suspension for farm vehicles with electro-hydraulic servo-mechanism was built as a trial and its characteristics were tested using a vibrator.
1. The active-seat suspension consisted of a seat, a servo-amplifier, a servo valve, a hydraulic cylinder, a hydraulic power source and a vibration sensing transducer (vibrometer).
2. For a vibration-sensing system, two methods of an acceleration-sensing system and a velocity-sensing system were used.
3. The vibrometer for the velocity-sensing system consisted of a horizontal pendulum, a spring supporting the pendulum and a relative velocity pick-up. There was a small difference in the mass of the pendulum about the axis of rotation. The natural frequency of the vibrator (ω0) became low by the moment of inertia of the pendulum. The principle was applied to the vibrometer that the relative velocity of the pendulum was proportional to the input absolute velocity when ω02<<ω2. It showed sufficient ability across the frequency band lower than 10Hz.
4. The response of the active-seat suspension was tested for sinusoidal and random vibration (the acceleration signals on the chassis of tractors and combines). In both of the accelerations sensing system and the velocity-sensing system, the acceleration of the seat showed a considerable decrease in comparison with the acceleration of the vibrator in the frequency range of 1 to 10Hz. In particular, acceleration transmissibilities were 0.1-0.5 in the frequency range of 2.0-5.0Hz.View full abstractDownload PDF (989K) -
[in Japanese]1980 Volume 42 Issue 3 Pages 451-454
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (648K) -
Mitsuo IIMOTO, [in Japanese]1980 Volume 42 Issue 3 Pages 455-456
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (390K) -
1980 Volume 42 Issue 3 Pages 457-460
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (5099K)
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