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Volume 37 (1975 - 197･･･
- Issue 4 Pages 481-
- Issue 3 Pages 289-
- Issue 2 Pages 149-
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Volume 37, Issue 2
Displaying 1-23 of 23 articles from this issue
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Performance of Turning MotionShigeo UMEDA, Nobuo HONAMI1975 Volume 37 Issue 2 Pages 149-155
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs one of the fundamental characteristics to evaluate the controllability and the stability of the travelling tractors on the ground, the cornering characteristics were discussed based on the experimental results obtained from the stational circular turning tests under the fixed steering angle.
(1) On the turning motions of the tractor, the turning radius increases according with the increase of the travelling speed in any case of the weight distributions on the front and the rear axle.
(2) The cornering powers, namely the relation between the side slip angles and the cornering forces, varies with the distributions of the weight on the front and the rear axle, and with the types of the tires, but not with the front wheel angles. In general, the tractors are equipped with different tires on the front and the rear wheel, and the cornering powers of the front wheels are less than the rear wheels. Therefore, it seems that the high degree of the understeering characteristics of the tractor is caused by the differences of the cornering powers of the front and the rear wheel tires.
(3) The cornering coefficient is nearly constant at any distribution of the weights on the axles. Therefore, as the fundamental characteristics value to evaluate the cornering characteristics of the tractors, the cornering coefficients are available.
(4) The tire inflation pressure of the tractor of the tractor on the ground, has little influence on the cornering characteristics. It is considered that the soil deformations under the tires are caused.
(5) The maximum values of the cornering force are defined with the coefficient of friction between the tire and the ground. Hence, in the case of the tractor with the steering front wheels of which cornering coefficients are smaller than the driven rear wheels, the side skid should be discussed in the way of limitation of understeering characteristics, on the directional stability of the tractor.View full abstractDownload PDF (818K) -
Theoretical and Experimental Discussion of Slip-draft Control SystemNobutaka ITO, Takahisa SAKAI, Katsuji MAEHARA1975 Volume 37 Issue 2 Pages 156-163
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA theoretical analysis of the slip draft control for the simulation model was reported in this paper. In the first part of this paper, Nyquist degree of stability, frequency response and indicial response of that simulation model were theoretically discussed.
Indicial response was also validated in the experiments. Available frequency response of this system was less than six Hz However this control system can be easily applied to the actual use, because the lifting and lowering frequency response of the implements such as plough or rotary unit should be low at running of vehicle.
For the application of this control system, the development of a direct indicator of tractor-wheel slip will be needed to make the operator's handling easier in the field work.
In further study the authors with to have more experiments for the practical applications using a actual farm tractor.View full abstractDownload PDF (831K) -
Isao YOSHIDA1975 Volume 37 Issue 2 Pages 164-170
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDrawbar-pull tests were carried out to study the relationshipships between travel reduction and drawbar pull using pneumatic tyres and model rigid wheels in our laboratory. As the result, relation between drawbar-pull/weight and travel reduction could be expressed by expression (1), and the optimum travel reductions which give the maximum work of wheel type tractors, and the optimum drawbar-pull ratios were recognized on drawbar-pull/weight-travel reduction curves.
The optimum travel reductions depend upon the coefficient B as shown in expression (7).View full abstractDownload PDF (2651K) -
Adaptability for Sweet Potatoes, Peanuts, Rapes and SoybeansToshio FURUCHI, Masateru NAGATA, Masabumi MITARAI1975 Volume 37 Issue 2 Pages 171-178
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESS1) The weeder for walking tractor was used once or twice during 10-20 days after planting of sweet potatoes, twice during 6-20 days aftet seeding of peannts, twice or thrice during 5-40 days after seeding of rapes and once during 14 days after seeding of soybeans.
2) Depth of tines of the weeder was 2.5-3.0cm and interval of locus of them was 1.25cm except some cases of sweet potatoes.
3) It was impossible to use the weeder when soil moisture was excess, because the clods which was cut by tines lay still between the tine and the tine. But it was possible to use the weeder smoothly in the normal soil moisture (when soil moisture was less than 36% in the loam soil).
4) When the weeder was used, height of crops, number of leaves, length of stalk, length of root, resistance for pulling out according to the kind of the crops, and those had influence on difficulties of using of the weeder.
5) Though the weeder was used just before germination time, the losing of peanuts and rapes were not recognized.
6) Generally, losing ratio of sweet potatoes, peanuts, rapes and soybeans were respectively 2.5-4.0%, 0-1.0%, 3-5%, 0.5-2.5%. Losing ratio of rapes was specially high when the weeder used at 1-2 leaf time.
7) Losing ratio of leaves and wounding ratio of stalk rather increased when the weeder was used for sewet potatoes and peanuts.
8) Generally, harvesting ratio of the weeding plot to the unweeding plot was 80% for sweet potatoes, and those of peanuts and rapes were 95-98%.
9) Losing ratio of weed in all kinds of crops were 70-95% and that increased when depth of tines of the weeder increased.
10) The adaptability of the weeder for peanuts and soybeans was good enough. There was no trouble for sweet potatoes and rapes if the weeder was used with care about the conditions of the operationView full abstractDownload PDF (2332K) -
Koichi HASHIGUCHI, Kunio MORIMOTO, Kang-Nang WANG, Shotaro MORISHIMA1975 Volume 37 Issue 2 Pages 179-186
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe mechanical proprieties of the slip line fields proposed by many workers for two-dimensional cutting process were examined, considering not only the stress states but the deformation states. Then Kudo's slip line field for metal machining with long cutting blade, which was acceptable for an upper bound solution, was extended for frictional soils and, hence, cutting resistance based on this field was calculated (Fig, 8(a)-(e)). By this calculation, the following results were obtained.
1. For the fixed value of cutting angle r, the effects of the parameters φ′ (external friction angle between soil and blade), φ (internal friction angle of soil) and c′/c (ratio of adhesion to cohesion) on the specific cutting resistande rc are larger than the others in order.
2. The larger φ′, the larger is the effect of φ on rc.
3. The smaller r is, the larger the effect of φ on rc is.
4. For the fixed values of r, φ′ and c′/c, the relation between φ and rc is nearly exponential.
5. The larger c′/c is and the smaller r is, the larger the ratio of increment of upper limit of rc to that of φ is.
Furthermore, comparing the above theoretically calculated values with the experimental values reported by the other workers, they have qualitatively the same trend (Fig. 9 and 10). In general, however, the theoretical values are larger than the experimental values. This may be due to the fact that slip line solutions, free body solutions and some other recent solutions are all based on Coulomb's law for perfectly plastic material. Hereafter more accurate theories which are free from the excess limit conditions such as Coulomb's law and take account of the effect of soil weight should be established.View full abstractDownload PDF (870K) -
Osamu KITANI1975 Volume 37 Issue 2 Pages 187-192
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe author applied finite element method to the calculation of the deflection and stress distribution of the furrow slice which behaved as elastoplastic material with strain-hardening characteristics.
As the first step geometric nonlinearity was neglected and compution was performed for the soil tilled by a plane blade with cutting angle of 30 degrees. The calculated stress distribution did not agree with the test results due to too much simplification including the neglect of cracks and geometric nonlinearity as well as the real boundary conditions.
Then calculations were made for the problem of finding the optimum angle of air jet injection from the plow share to the soil. The injection angle was varied from 30° up to 90° and the corresponding soil stress distributions and deformations were observed. The effect of the change of the angle was significant. The calculated results as well as the experimental ones showed that larger angle was more advantageous.
The application of finite element method for the tillage problem is, at present, limited to this kind of special problem. It will become, however, more valid in the future when the above mentioned factors are taken into consideration.View full abstractDownload PDF (739K) -
Electrostatic Generation in the Boom Duster pipe, and Investigation and Application of Pressure in the Pipe with ComputerYasuo MASUDA1975 Volume 37 Issue 2 Pages 193-202
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESS(1) We examined how the static electricity was generated in the boom duster, depending upon the kinds of powders and relative air humidity
(2) We examined the effects of the chemicals to prevent the electrification painted on the inner pipe wall on the kinds of powderes.
(3) Two kinds of powders; Kaolinite and Bentnite showed a similar state of electrification; that is, positive near to the blower in the 10-m pipe, negative in the middle and positive or zero at the end of it. The value of the former was lower. Contrary to these two, the state of electrification of Talc was as follows; negative near the blower in the 10-m pipe, zero in the middle and positive at the end of it, and the absolute quantity of static electricity of Talc was lower than that of the outer two.
(4) It became clear that the effects of the chemicals to prevent the electrification were not so remarkable, but had some influence.
(5) The electrostatic charge was very low at humidity above 70% and it showed a violent variation between positive and negative at humidity 40-50%.
(6) We made calculations to determine the inner pressure of the pipe.
(7) Before the experiment descrived above, we examined the approximations of measured values and calculated values. As for the static pressures, the approximations at the end of the pipe were rather low and, as for the dinamic pressure, so were those near the blower, but the approximations as a whole were close in each case.
(8) Assuming all the orifices of the pipe spout an equal amount of air, we made calculations as to the distributions of the static pressure and orifices, depending upon the diameter of the pipe, the distance between each orifice and the orifice diameters at the pipe end.View full abstractDownload PDF (5321K) -
Effect of Sound on Heat Transfer from a Single Copper SphereSadato ISHIBASHI, Shunichiro TANAKA, Masayuki HIRATA1975 Volume 37 Issue 2 Pages 203-208
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe authors intended the application of low frequency sound waves which scarcely generates any heat durring the drying of agricultural products. In this paper, we tried a few experiments on the effects of position of the sphere in a standing sound field, sound pressure and frequency on heat transfer from a single copper sphere. A summary of the results is shown below.
1) The effect of position of the sphere in a standing sound field on heat transfer from a copper sphere was evident. No relationship between sound pressure and Nu number was found at antinode. However, Nu number increased from about 145dB at node. That is, the heat transfer from a copper sphere increased when it was located at node which had maximum particle velocity.
2) Nu number increased with sound pressure (that is to say, particle velocity).
3) Aeration affected sound pressure level from which Nu number began to increase. Nu number increased from about 145dB when air velocity was zero. On the other hand, it was 148dB when aeration was performed.
4) The lower the frequency, the larger was the Nu number.
5) The following relation between Nu number and (Re)a number within the limits of this experiment was obtained.
Nu=h.D/K=K(Re)a0.19
where 6.6<K<8.6 for 0<Re<900
6) Electric power required for speaker driver was given by a exponential function of sound pressure. A resonant frequency of the tube did not show a special increase in Nu number as compared with the other frequencies, but the electric power required was less than the others.View full abstractDownload PDF (755K) -
Yoshio NISHIYAMA, Akira HOSOKAWA1975 Volume 37 Issue 2 Pages 209-216
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this paper the authors presented an effective method of calculation for grain intermittent drying, of which no theoretical analysis had been made. The calculation method is besed on the Sphere Drying Model, with computation of the moisture content of a unit sphere being dried intermittently.
Summary of the calculation procedure is as follows;
1. Defintion of non-dimensional time X
X=Kt (Sphere Model) or=Kt+X0 (Modified Sphere Model)
2. Single Scage Intermittent Drying
2-1. 1st Drying Period
Average moisture moistent M(X1) is calculated by eq. (21) using function Φ(X). Moisture content distribution C(X1, r) is obtained from eq. (19) using function Φ(X, r).
2-2. Intermission Period
Moisture conted distribution Ci(X2, r) is obtained from eq. (27) using function Φi(X1, X2, r).
2-3. 2nd Drying period
Average moisture content M2(X3) is calculated by eq. (37) using function Φ(X1, X2, X3), and moisture content distribution C2(X3, r) is by eq. (34) using Φ2(X1, X2, X3, r).
3. Multi-stage Intermittent Drying
‹proc. 0› (initial set): f(r)=M0
‹proc. D› (drying period): Average moisture content M(X) is calculated by eq. (8) and moisture content distribution C(X, r), by eq. (5). At the end of this procedure, make f(r)=C(Xdl, r).
‹proc. I› (intermission period): Ci(X, r) is calculated by eq. (5), and at the end of this procedure, make f(r)=C(Xil, r).
Average moisture contents and moisture content distributions of each drying period are obtained if computations are repeated as;
‹Proc. 0›→‹proc. D›→‹proc. I›→…‹proc. I›→‹proc. D›
The author also showed quite good agreement between the drying experiments and computations (see Fig. 7 and Tab. 1).View full abstractDownload PDF (870K) -
1975 Volume 37 Issue 2 Pages 216
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (110K) -
Application for Bulk Bin StorageJuzo MATSUDA, Kazuhiko ITO, Yoshinori IKEUCHI, Tomiho YOSHIDA1975 Volume 37 Issue 2 Pages 217-221
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis investigation was carried out to find out the availability of the drying and storage plant attached to the Country Elevator of MUKAWA Agricultural Cooperative Association in Hokkaido. Following the previous report, this paper is a report of investigations conducted to determine the storage chracteristics of paddy, using DRYSTORE as a bulk storage facility.
In this investigation, 9 of 40 bins were used as storage bins.
The temperature of various place of this plant and stored paddy were measured, and other measured items for determining the quality of stored paddy were moisture content, germination viability and fat acidity.
The results obtained are as follows.
During the investigation period, there were large diurnal fluctuations in temperature and atomospheric conditions seemed hard for paddy storage. However the influence of temperature on stored paddy was slightened because of the insulating material (thickness: 50mm) with which the surrounding walls of storage bins were covered thoroughly.
While only 9 bins (416 ton) were loaded in the first year (1971), in the next year (1972) all bins were loaded with 2270 ton of paddy. In both two times of storage tests, most of stored paddies were kept at low temperature and the qualities of stored paddy were not deteriorated. And the storage characteristics of this plant in 1971 tests were not so different from in 1972 tests.View full abstractDownload PDF (679K) -
The Motion of WireYuei TABA, Noboru KAWAMURA, Shunichi OKAMURA1975 Volume 37 Issue 2 Pages 222-228
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe circular frequency of wire which was fixd at one end on a rotating stripping drum at uniform angular velocity was calculated by changing the fixing angle of wire and the rotating speed of stripping drum. The motion of wire deflected during the process of stripping cane leaves was analyzed in the racing of stripping drum between the position where wire took off sugarcane and the position where wire again collided with sugarcane, and the state of wire at the collision of wire top with sugarcane was investigated theoretically.
In order to estimate the dynamic force acting at the top of wire during the process of stripping cane leaves, the octagonal ring with plate for force transducer was put on the place where was at equal distance from upper and lower stripping drums of wire type sugarcane stripping machine, when the stripping drum was rotated at uniform angular velocity, the normal and horizontal forces acting at the top of wire rubbing the plate on octagonal ring was measured, and the direction and magnitude of acting force was obtained.
In order to confirm the theory of the motion of wire, the photographs of the state of wire in motion was taken with stroboscope.
The esults obtained was as follows.
(1) As the fixing angle of wire and the _rotating speed of stripping drum increased the circular frepuency of wire increased.
(2) The circular frequency of wire and the rotating speed of stripping drum significantly influenced the state of wire deflection at the collision of wire top with sugarcane.
(3) The force acting at the top of wire was influenced considerably by the state of wire deflection at the collision of wire top with sugarcane.
(4) When the rotating speed of stripping drum was lower, the acting force of wire was maximum at the place where the wire top took off sugarcane, and was large in the direction of the axle of wire, as the fixing angle of wire incleased the force of direction of the axle of wire decleased.
(5) When the rotating speed of stripping drum was higher, the acting force of wire was maximum at the collision of wire top with sugarcane, and was large in the direction perpendicular to the axle of wire.View full abstractDownload PDF (2617K) -
On the Edge-Angle and Abrasion of Japanese-HoesJiro SATO1975 Volume 37 Issue 2 Pages 229-234
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe experiments were carried out to prove that, in the case of using a Japanese hoe, it is from the difference of the steel, alloy layer and base metal of the blade edge, that its edge is worn out at a certain angle.
The results were as follows:
1) Blade edge in which Nabehagane and Zenihagane were used as steel usually had alloy layer.
2) In a used Japanese hoe there was a change in the thickness of steel and base metal, and not in the thickness of alloy layer and in edgeangle.
3) As for hardness, Nabehagane was the hardest, Zenihagane was the second, Carbon-tool-steel was the third and base metal was the last. And in alloy layer the upper part was harder. And Nabehagane and Zenihagane became softer after they were crashed, heated, and cooled, and they became harder after they were crashed, heated, melted and cooled.
4) As for thickness of alloy layer, the upper layer was thicker, and it thickened by prolonged heating time.
5) Both Nabehagane and Zenihagane became harder by forging.View full abstractDownload PDF (4311K) -
Yasuhisa SEO, Akira HOSOKAWA1975 Volume 37 Issue 2 Pages 235-240
Published: 1975
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThie study was done to find the posibility of automating processes of current commercially practised banana riping which has been operated by experienced and skilled operators.
(1) The experiment of banana ripening with 3.38kg of banana was conducted in a chamber of 51.8 1 made of transparent plastic plates. The temperature in the chamber was controlled to provide the chamber with the same ripening temperature schedule as in the banana ripening room which had been investigated before. The chamber was ventilated by a small air pump at the time when CO2 concentration in the chamber reached about 8.0% since this was the case in the ripening room. The results of the experiment made good agreement on sugar content, color grade and hardness of pulp of banana with those of the ripening room. This could be considered that the experiment indicated the possibility of automation of banana ripening.
(2) To put automation of banana ripening into practice, development of reliable and inexpensive CO2 analyser will be required. Banana ripening in a plastic film tent will deserve to be taken up for study to develop a new method for simple and economic benana ripening.View full abstractDownload PDF (781K) -
[in Japanese]1975 Volume 37 Issue 2 Pages 241-243,253
Published: 1975
Released on J-STAGE: April 30, 2010
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[in Japanese]1975 Volume 37 Issue 2 Pages 244-245,253
Published: 1975
Released on J-STAGE: April 30, 2010
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1975 Volume 37 Issue 2 Pages 246-250
Published: 1975
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1975 Volume 37 Issue 2 Pages 251-252
Published: 1975
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1975 Volume 37 Issue 2 Pages 253
Published: 1975
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1975 Volume 37 Issue 2 Pages 254-267
Published: 1975
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1975 Volume 37 Issue 2 Pages 283a
Published: 1975
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1975 Volume 37 Issue 2 Pages 283b
Published: 1975
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1975 Volume 37 Issue 2 Pages 283c
Published: 1975
Released on J-STAGE: April 30, 2010
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