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Volume 27, Issue 2
Displaying 1-19 of 19 articles from this issue
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1965 Volume 27 Issue 2 Pages 61-70
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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M. SONOMURA, Y. SHIBANO1965 Volume 27 Issue 2 Pages 71-73
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this report, the cooling performance of farm air-cooled engines with three types of the radial fan, were compared, and the following results were obtained. A higher cooling efficiency was attained by blades curved backwardly.
As for the size of the fan, the forward bent blades can be made smaller than those of the fan with the radial outlet blades or the backward bent blades for equal speed and wind pressure head.
For this reason, it seems that the engine required smaller size ought to employ the forward bent blade fans.View full abstractDownload PDF (474K) -
J. DOI, Y. YASUDA1965 Volume 27 Issue 2 Pages 74-80
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSRelations between the traction performance of a wheel tractor and the wheel slippage were studied. The slip ratio which gives maximum tractive power lies in a little lower value from the slip ratio which gives maximum tractive force.
Maximum traction slippage differs according to the traction speed, but it was observed that slippage is closely related to the slip speed. In these experiment, maximum traction was observed at the slip speed of 0.2m/s. In this case, maximum tractive power is expected at the driving speed of 0.5m/s, which is the rating speed of the first gear.
For the stability of the traction, operating point should not exceed the maximum traction slippage. Motion of the tractor in the unstable zone may be described by the Van del Pol equation. Solution of the equation using electronic analog computer gives fair agreement with the experimental results.View full abstractDownload PDF (1172K) -
1965 Volume 27 Issue 2 Pages 80b
Published: 1965
Released on J-STAGE: April 30, 2010
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1965 Volume 27 Issue 2 Pages 80a
Published: 1965
Released on J-STAGE: April 30, 2010
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Vertical Motion of a Tractor and a Hitched PlowJ. DOI, Y. YASUDA1965 Volume 27 Issue 2 Pages 81-86
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDynamics of the system with a tractor and a hitched plow are discussed with respect to their vertical motion.
Frequency response of a 35 PS tractor with a single plow is around 0.1-0.3c/s and the characteristics are approximated to a first order response under normal operating condition.
In ordinary uncontrolled 3 points link hitch, existence of the control spring which locates at the end of the top link is not necessarily useful to maintain the stability. And viscous resistance to the motion of lift arm is also not necessarily effective for the stability.View full abstractDownload PDF (745K) -
On the Convenience of Mounting and Dismounting, Front-visibility and Comfortability of SeatM. SAKAI1965 Volume 27 Issue 2 Pages 87-92
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSStatical measurements of tractors (18 domestic and 16 imported) suggested several problems to be improved or corrected as follows.
(1) Convenience of mounting and dismounting: The steps of imported tractors are about 24% higher than domestic ones, and are not adequate for Japanese phisique. Access for mounting and dismounting are too narrow in both domestic and imported tractors. The worst case is found in the longitudinal dimension of a access of a certain domestic tractor, which is negative.
(2) Front-visibility: The average invisible area of domestic and imported tractors is 1.56m2 and 2.53m2, respectively.
(3) Suspension of seat: Most domestic tractors use gum-torsion suspensions which are simple to manufacture, bnt require larger energy consumption for operators.
(4) Shape of seat: Most domestic tractors are equipped with bucket-type seats, which have many physiological faults. Regardless of makes or countries, the shape and structure of tractor seats seem to need improvements to be not resonant with operators' bodies.
(5) Dimensions of seat: Both height and width are too large for Japanese operators in case of imported tractors. On the contrary, those of domestic tractors are generally too small. The depth of seat is nearly the most appropriate in imported tractors, but too small in a half of domestic.
(6) Inclination of seat surface: The greater part of investigated tractors has no inclination, those of the remainder are stronger than the optimum (4 to 6 degrees to horizontal line).
(7) Adjustability of seat position: A majority of tractors has no adjustment devices. Even in the remainder equipped with such devices, the adjustable range is not sufficient for the optimum (1/8 to 1/9 of stature).
(8) Accessories of seat: The heights of backrests have appropriate dimensions (about 220mm over the seat surface) except four tractors, in which the height is either short or exceeding. Except five domestic tractors, footrests have no inclination, the most suitable angles of which are 28 to 30 degrees to horizontal line.View full abstractDownload PDF (2292K) -
On the Efficiency of the One Way PlowC. IGAKI1965 Volume 27 Issue 2 Pages 93-97
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs explained in the previous report, the utilization of one way plows can be deviled into two types, that is, two kinds of treating inner-side of the field and five kinds of treating head land. The efficiency value can be calculated by dividing the distance of plowing by the total distance of running including the futile run, but to get more correct value the time of gear change and decrease of the dis tance of reversing must be rearranged to the distance of the futile run.
In this way, values of E are shown by each plowing method in Fig. 1-6. In the calculation we used 3 kinds of tractor A, B and C, and the slendenees rate of the field is 1/1-4/1, and the are a is 202-1002m2 If we use the followed plowing methed in the inner-side, the value of E rises rapidly by in crease of area, but when we use the normal plowing method it is not effective. Also in either case, increase of the slenderness-ratio have a great influence on the rising tendency of E value. As a counter-measure, the short side is to be divided to decrease the distance of the futile run on the short side B. When we divide the square field, the side length of which is 20, 40, 60, 80, and 100m, into 1, 2, 3, 4, 5 blocks, we get the value of B as shown in Fig. 7 In this figure, we recognize the value of E increase more rapidly than former values. Comparison on the efficiency curves of each plowing method are shown Fig. 8
In short, for decreasing the loss of dis tance and increasing the valve of E, we may use the followed plowing method, But as the other way, if we split the inner-side into short width form, the distance of the fntile run in the inner-side will be decreased. Moreover if we use the above method together with the semi-followed plowing method in the cicumference, the valne of E will rise considerably and it may be more profitable than the other methods.View full abstractDownload PDF (721K) -
Soil Failure Tests under Various Methods of Force ApplicationO. KITANI1965 Volume 27 Issue 2 Pages 98-104
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to verify the stress theory which the auther reported before, a series of soil failure tests under various methods of force application—compression, tension, torsion and cutting—were conducted. Two micro soil stress meters were buried so that they picked up the summation of two principal stresses in solid cylindrical soil specimen. The applied force, displacement and energy were also measured. Tests were run for three kinds of soil—sandy loam, clay loam and clay. The main results are the followings:
1) The stress theory is qualitatively right.
2) The energy consumption for compressive shear failure is more than 30 timens as large as that of tensile rupture.
The enengy of tensile-tortional failure is several times as much as that of tensile rupture.
3) According to the difference of soil texture, the characteristics of soil failure are varied. For instance, the more clay content, the more the energy requirement for conpressive shear and tensile rupture, Whereas, cutting failure shows a quite contrary tendency.View full abstractDownload PDF (1046K) -
On the Pressure of Soil Raise and the under Soil PressureS. MORISHIMA, K. KOJIMA1965 Volume 27 Issue 2 Pages 105-107
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWe have measured the pressure at soil raise and the under soil pressure when piercers are pulled through the sandy loam and clay loam.
The results are as follows.
1) It seems that the pressure at the sandy loam raise is larger than the clay loam, but in the case of the small relative density, there is not so evident difference between the sandy loam and clay loam.
The pressure at soil raise has nothing to do with the tip angle of ball.
2) The under soil pressure near the ball is larger than that far from the ball in the case of a little soil raise, but is not so large on the whole in the case of more soil raise.View full abstractDownload PDF (479K) -
1965 Volume 27 Issue 2 Pages 107
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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Particle Distribution Curve of Crushed Products by Open Circuit MethodS. ISHIBASHI, S. YOSHIZAKI1965 Volume 27 Issue 2 Pages 108-110
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe authors investigated about particle distribution curve of some grains crushed with the hammer bar type mill used in the first report by open circuit method.
The following results are obtained.
1. Independent of crushing conditions, the particle distribution curve of grains by open circuit method satisfies the Rosin-Rammler's law.
2. At specific speed of rotation of hammers, the index n of Rosin-Rammler's formula decreases rapidly when the flow rate of grains to be crushed arrives at specific values.
3. The index n is little influenced by the number of hammers, and is inversely proportional to the diameter of holes in screen.
4. Within the definite specific range of the speed of revolution of hammers (r. p. m) the index n increases a little in accordance with it.View full abstractDownload PDF (437K) -
Fineness Modulus, Uniformity Index and Power Consumption Concerning the Crushed Products by Open Cicuit MethodS. ISHIBASHI, S. YOSHIZAKI1965 Volume 27 Issue 2 Pages 111-115
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe authors tried to know the relationship between crushing conditions and Uniformity index, Fineness modulus and Power consumption of crushed products.
The following results are obtained.
1. Fineness modulus increases according to the increase of the diameter of holes in screen and the flow rate of grains to be crushed, and on the contrary decreases when number of hammers increases from 4 to 16. It decreases linearly when the speed of revolution of the hammers increases from 2, 600r.p.m to 3, 600.
2. There is the following relation between the power consumption P and the flow rate of grains Q P_??_Qm
where m=an index influenced by the crushing condition
3. In the experimented mill the minimum dower consumption is obtained when eight hammers are set.
4. Within the range of the diameter of holes in screen 2.0mm to 6.0, there is the invevse from relationship between the power consumption and the diameter of holes.
5. According to the increase of the speed of rotation of hammers from 2, 600r.p.m to 3, 600 the power consumption gradually increases, and becomes nearly constant over 3, 000 r.p.m.View full abstractDownload PDF (706K) -
On Application to Bulk Curing of Tobacco Leaves for the Solid Drying TheoryK. NOGUCHI, Y. KINOSHITA1965 Volume 27 Issue 2 Pages 116-120
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe authors analyzed the changes of moisture content of tobacco leaves in practical bulk curing unit making use of the solid drying theory, and found the curing process of tobacco leaves are formed of the material heating, the constant rate and the first and the second falling rate period in turn. As the value of drying rate, critical moisture contents, coefficient of surface evaporation, film coefficient of air in the above-mentioned four periods are certainly requried to theoritical analysis on this process, the authors constructed experimental curing burn in small scale adjusting temperature, humidity and velocity of air, and investigated the above-mentioned values. Results obtained were as follows.
(1) The period of constant rate drying mixes with the material heating period, and the value of drying rate in these periods is 1-2×10-3kg/hr·m2 (where kg: moisture evaporated from leaves, m2: leaf areaes of two sides). When this value increased to 6×10-3kg/hr, m2, these periods finish. These periods are just equall to the middle of color fixed stage of tobacco leaves. Then after that, the first (the value of drying rate in this period is 2-3×10-3kg/hr·m2) and the second falling rate period go on to the end of drying without a break.
(2) Critical moisture content is generally consist between the period of constant rate' drying and falling rate drying. On tobacco leaves, this value is about 200-300% of dry basis moisture content.
(3) In the semi-constant rate period, the value of coefficient of surface evaporation (α) is 0.3-0.4×10-3kg/hr·m2. mmHg (where mmHg: difference between vapoure of air and saturated vapour pressure for leaf temperature). This period is just equall from the yellowing stage to the early color fixed stage of tobacco leaves. But this value gradually increases to 0.6×10-3kg/hr·m2. mmHg, and decreases again to 0.3-0.4×10-3kg/hr·m2. mmHg in the falling rate period.
(4) In the early stage of first falling rate, the film coefficient of air (α′) is about 1kg*/hr·m2 (where kg*: weight of dry air), but in the end of the stage this value decreases to 0.1-0.3kg*/hr·m2. This period is just equall after the middle of color fixed stage of tobacco leaves.View full abstractDownload PDF (907K) -
[in Japanese]1965 Volume 27 Issue 2 Pages 121-122
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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[in Japanese], [in Japanese]1965 Volume 27 Issue 2 Pages 122
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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[in Japanese]1965 Volume 27 Issue 2 Pages 123-126
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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[in Japanese]1965 Volume 27 Issue 2 Pages 127-135
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
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1965 Volume 27 Issue 2 Pages 135-137
Published: September 01, 1965
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (667K)
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