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Volume 27, Issue 3
Displaying 1-14 of 14 articles from this issue
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1965 Volume 27 Issue 3 Pages 143-145
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (204K) -
Some Analysis for System of Kinetic Force of Tractor BodyR. TAKEUCHI1965 Volume 27 Issue 3 Pages 146-149
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSCharacteristics of vibration at tillage work was found by theoretical calculation of vibrating acceleration at power tiller's body, and compared with load factor. The author applied a motion system of tiller to a substituting matrix system and calculated the deflection at driving point. It was found that there is a particular point in stress, load factor and amplitude within 6-10cm of tilling depth with this tiller. Most effective tillage depth is within 15-20cm, regarding from the aforesaid points, but practically, influence of hardness of soil and reaction of tilling resistance are to be considered.
Next, six formulas was gotten by analysis of system of motion which is accmpanied by working state, but the maximum deflection was produced at the axis of shaft in case of neglecting rolling deflection compared with pitching.
Solving the coalition equation of deflection of each parts of tiller's body, it resulted that the rolling deflection is larger than pitching. Consequently it is considered that rolling performance is the most important.View full abstractDownload PDF (594K) -
Measuring Device of the Soil Parameters, TN-4T. TANAKA1965 Volume 27 Issue 3 Pages 150-154
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe self-recording device for measurement of soil values named Soil Values Meter TN-4 was designed and tested in our laboratory. Many various soil values, cone index, shear resistances of the soil surface, internal friction coefficient of soil tanφ′ cohesion c, friction between soil and tires tanφ′, Bekker's modules of soil deformation kc, kφ, and exponent of soil deformation n, etc., can be measured by this device simply by self-recording system.
Measurement can be done by only one person and this device reduces the time and labor for transcribing and rearranging to the chart from the data in conventional non-self-recording devices.View full abstractDownload PDF (862K) -
Vertical Motion of a Controlled PlowJ. DOI, Y. YASUDA1965 Volume 27 Issue 3 Pages 155-161
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDynamics of a plow which is controlled with a hydraulic device are discussed. Summary of the conclusions are as follows.
1. Stability of the draft control and position control system is kept for hard control spring, high loop gain and small timeconstant of theh ydraulic system.
2. Restoring orientation of 3 points link hitch mechanism is equivalent to the feedback of the powerpiston.
3. From the viewpoint of stability in higher frequency domain or in higher tractor speed, pneumatic control is more adequate than hydraulic control.
4. Vertical spring constant at the hitch point becomes greater when controlled hitching mechanism is employed. And more quick response of the plow and the effective weight transfer are expected.
5. Quick response of the plow is brought by the great loop gain and small time constant of the control system, however, limitation of the performance is existed. For an example of a 35 PS tractor, the limitation of response locates around 0.5sec. of overall time constant.
6. Vertical position variation due to the rear wheel load variation which is resulted from the control action decreases the controlled performance. Soft ground and soft pneumatic tires are unsatisfactory from the standpoint.View full abstractDownload PDF (1111K) -
A Study on Vibrating Tillage MethodO. KITANI1965 Volume 27 Issue 3 Pages 162-167
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe main aim of this study is to clarify the reason of comparatively small resistance of vibrating tillage tools.
At first, the author estimated the acceleration energy of soil in high frequency vibration tillage. It proved to be comparativ to the energy for cutting soil with the same blade at very low speed.
Then, a series of tests were conducted, varying the distance of forward travel and backward travel in one cycle motion. The resistance force was measeured. The stress distribution in the soil was measured by micro soil stress meters. The pictures of soil deformation were taken through the side window of the soil bin.
The tensile stress in the soil during backward travel and the tensile rupture of the soil near the blade edge were detected. The loosening of the soil above the blade was observed. These rupture and Loosening action contribute to the reduction of resistance.View full abstractDownload PDF (3312K) -
On the Efficiency of the Two Way PlowC. IGAKI1965 Volume 27 Issue 3 Pages 168-171
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSConcerning the calculation of the plowing efficiency by the two way plow, 2 turning methods, medusa type and cycloid-type are selected from 5 methods in order to avoid complication.
The tractors used in this calculation are shown in Tab. 3, and 2 tractors are reversible type.
Every corrected calculation formula of distance of futile run about each turning method is shown in Tab. 4.
By appling the value of each tractors into the Tab. 4, we can get the efficiency value as shown in Fig. 1-3 about the medusa type, and Fig. 4-6 about the cycloid type.
On the cycloid type, it is obviously find out that if short side of the field B was divided into 2n parts, the ratio of A/B becomes large, and therefore the distance of the futile run becomes short.
Efficiency curve of the special type tractors, B″ and D″, are shown in Fig. 7. In this case, the distance of futile run, is very small and its advantage would be easily understood.
Fig. 8 shows efficiency curve of each method about B and B″ tractors the latter of which is improved from B.
In the case of using over-line turning method, the special type shows the highest value, and also in general case, the additional plowing method (for B line) have an advantage by using B″ tractor.
But in the case of using the normal tractor, method of the cycloid type shows a tendency of high efficiency value.
The efficiency value of the cycloid-type given here, is calculated by dividing short side width B into 10m each. Therefore, the efficiency eurves change its position ley this divided width. If the width of short side is fairly large, the efficiency curve of the special type tractor becomes higher than the value of the cycloid type, and the special tractor will be suitable to use in all case.View full abstractDownload PDF (598K) -
On the Shearings of SoilK. KOJIMA, I. SIMOMURA1965 Volume 27 Issue 3 Pages 172-177
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAn extensive study has been carried out on the shearing conditions of soils given by the penetrati on of various model piercers into the sandy loam and the loam having various densities and water contents.
1) The shear cracks occurred by the penetration were accompanied with the increase of soil water contents the depth of the penetration and the extreme angle of the ball, but were not effected by the densities of soil.
2) The water contents that the shear cracks are difficult to occur in the case of the sandy loam and the loam were 20% and 25% respectively. The shear cracks are also difficult to occur when the depth of penetration was five times of ball diameter.
3) The side shear crack angle that was measured from a level surface was nearly 45°-φ/2 (φ is angle of the internal friction). From these results, it seems most reasonable to conclude that the shear crack occurred by the passive earth pressure.
4) When the ball pierced through the shallow place, the front shear crack occurred by the passive earth pressure.
5) The distance that the ball pressed forward the soil was from three and a half to four times of ball diameter, but it was not related to the depth of the penetration, the density of the soil and the extreme angle of the ball.View full abstractDownload PDF (4355K) -
T. TAKENAGA1965 Volume 27 Issue 3 Pages 178-184
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIt is the recent research in the studying circles of the pest control, that applicates the granuler chemicals such as the herbicide and insecticide to the paddy fields by the granular applicator, except for the granular fertilizer with use of the broadcaster to upland fields. Before the studies, it is not only important for the planning and designing of applicator, but also for secureing the pest control effects, to investigate the fundamental characters of the application of granules.
The results of these studies are as follows:
1. The fitting ranges of diameter of granules on the mechanism of applicator and the effects control were from 0.3 to 1.25mm, and its probability density function will be expressed by the normal distribution function of Gauss.
2. The constant discharge of granules through the adjusting shutter which is situated in the bottom of the tank is essential, because the uniform distribution on the field surface is expected by constant discharge. Moreover, to keep the constant discharge, the angles of repose and the moisture contents of granule should be in the suitable ranges. In this study, it was found that the angles of repose are 36-38 degrees, and the moisture contents are not exceeding 20% in weight, when the carrier of granular chemicals is the bentonite.
3. The application rate of granular chemicals is 3kg per 10 ares which was recommended by the studies of agricultural chemicals. In the mutual relations between the rate of work and the discharge from applicator, the areas of adjusting shutter are important factors for the uniform effects. In this study, it was decided that the ranges of shutter areas are about 40-80mm2, when the applicating times of 3kg are about 5-15 minutes, using the granules, ranging from 0.3 to 1.25 mm diameter.
4. In general, the tank must have the agitator in the bottom to keep the continuos discharge. But it is not always necessary for this granular applicator to provide the agitator, when using the above mentioned shutter areas and distribution diameter of granule.View full abstractDownload PDF (1207K) -
S. ISHIBASHI, T. ABE1965 Volume 27 Issue 3 Pages 185-187
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe terminal velocity of a particle is determined by dropping it in still air, but present experiments were designed to provide relative air velocity on seed grains suspended in the air flow, and it was done with grain particle group. The following grains were investigated—corns, soybeans, rice, and hulled rice seeds. Within the limits of these data, it was found that the terminal velocity of grain particle group decreases as the weight of grains increases, for air displaced with grain group is not negligible.
This tendency is more remarkable when the grain has rough surface.
Next, the relation between pressure drop and mean air velocity were investigated. The resistance to flow through the grains increases more rapidly in the case of smaller grain.View full abstractDownload PDF (460K) -
The Importance of Scythes in Hay HarvestingN. HAYASHI1965 Volume 27 Issue 3 Pages 188-193
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAccording to the agricultural statistics of Japan in 1904, about 400 thousand farms fed about 1200 thousand cows (average 3.1 cows a farm). Among them feeding 10 more cows a farm are only 1%. Farm mechanization is hardly performed besides tilling and ensilase cutting, so in harvesting the most farms use sickles. Sickles being used in harvesting, the labor hours used in harvesting is 40-80% of the total labor hours (tilling, manuring, seeding, harvesting, cutting).
In Japan, although the number of cows increases 120 thousand a year in the recent 3 years (so we shall have 2 times of cows by 1974), yet average farm of Japan has only 1 hectare. So the mechanization by 4 wheel tractors cannot be expected in Japan.
We did not use scythes or cradles in harvesting before, but recently in some farms scythes begin to be used in harvesting. The Author intended to estimate the roll of scythes and made it clear that the scythe is the important means at the stage of mechanization in Japan, for the sickle is still used by the most of farms. The efficiency of using scythes or sickles is decided by the strength of laborer, sex, the length of labor hours, the skilfulness of laborer and the sorts of grass. So it is vary difficult to calculate the efficiency exactly. In this investigation, it was found that using sickles and scythes the time of labor is increased with the amount of grass, but using the tractor the time of labor is dependent on the area of land. Average time required for harvesting 1000 kg of grass is 2 hours by using scythe and 6 hours by using sickles. The properties of the scythe of Japan comparing with Austria will be dealt with in the next report.View full abstractDownload PDF (1040K) -
[in Japanese]1965 Volume 27 Issue 3 Pages 194
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
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[in Japanese]1965 Volume 27 Issue 3 Pages 195-198
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (663K) -
[in Japanese]1965 Volume 27 Issue 3 Pages 199-202
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (4952K) -
1965 Volume 27 Issue 3 Pages 203-206
Published: December 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (641K)
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