農業機械学会誌
Online ISSN : 1884-6025
Print ISSN : 0285-2543
ISSN-L : 0285-2543
27 巻 , 4 号
選択された号の論文の12件中1~12を表示しています
  • 1966 年 27 巻 4 号 p. 207-217
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 田中 孝, 西村 功, 東 富夫
    1966 年 27 巻 4 号 p. 218-224
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The drawbar pull tests of the farm tractors were carried out on the soft paddy field. Six tractors and various running elements such as pneumatic tires, half tracks, strake type wheels, girdles and dual tires were used.
    Field conditions were (1), stubble land of rice plants, humid, clay soil, internal friction angle of soil were 23-24 degree, (2), the field after harvesting the Chinese milk vetch, loamy clay soil, internal friction angle 13°-14°, (3), submerged field after rotary tilling, (4), fallowing land, after harvesting the rice plants, loamy clay soil, internal friction angle 34°-36° at a-d section, 23°-25° at e-f section and 14° at h section.
    1. The drawbar pull were dropped as the broken lines in figures 2-9 and having the peak values at 30-40 percent slippage of the running elements when the fibers of the withered weed or hay stuck to the surface of the tires or shoes of the half tracks with the sticky soil.
    Maximum drawbar pull increased as the continuous lines in the same figures by removing of the sticked soil and weed fibers. The mean values of the ratios of dropping were 20.6 percent at the tire and 28.2 percent on half tracks for the maximum drawbar pull. The largest decrease was seen in the case of the tire as 40 percent. On the strake type wheel used at subsurface crossing in Bekker's discussion, these phenomenonons were not caused. To give the trong tension to the half tracks had an effect to eliminate these stick ed soil from the tracks.
    2. Drawbar pull was increased by attaching the half track or the strake type wheel to the tire. In the test field (2) the increases was 1.98-2.1 times for half tracks and 1.7-1.9 times for the strake wheels. In the test field (4) 1.4-1.7 for half tracks, 1.37 for girdles and 1.3-1.7 for dual tires.
    3. On the submerged field after rotary tilling, the drawbar pull we resmaller than that of non-submerged field and the ratios of decrease in the strake type wheels were smaller than that of half tracks, that is, the drawbar pull of the strake type wheel on this field kept the 81 percent of the drawbar pull in the test field (2) while that of the half tracks decreased to 54 percent.
    Under these soil conditions, the strake type wheels and lug wheels used usually in Japanese small power tillers, though they belong to the subsurface crossing methods in Bekker's discussion, displayed the splended performances, while the drawbar pull of the half tracks or tracks, which belong to the surface crossing, were very poor.
  • 田中 孝, 西村 功, 東 富夫
    1966 年 27 巻 4 号 p. 225-230
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The measurements of sinkage of the various running elements of the several farm tractors, such as wheel type, half track type, strake wheel type, girdles and dual tires, having the various drawbar pull loads were tested on the wet paddy fields. Summarized results of this test are as follows.
    1. Sinkage of the running elements of the tractor increased with increase of the drawbar pull and the relation curves between both factors were quite similar with the curves of the drawbar pull vs. slippage reported previously in Part IV of this series. On the fields having the dropping phenomenons of the curves of the drawbar pull vs. slippage, the quite similar relations of the drawbar pull vs. sinkage were shown as the broken lines in the figures in this report.
    2. Then, we can get the linear relationships between the sinkage and the slippage of the running elements of the tractors with the increase of the drawbar pull, except the sinkage at 100 percent slippage, which was excavated by the treads of wheelsor tracks.
    3. Half tracks used as semi-crawler type tractor had better floatations and less sinkage than tires. Sinkage of the strake type wheel were larger than that of tires or half tracks by the depth of projecting parts.
    4. Comparatively hard field in the wet paddy fields, the surface crossing type such as half tracks had less sinkage and larger drawbar pull than subsurface crossing type as strake type wheel. On the other hand, on the fields havinig the soft layer on the top of them, as puddling field, the surface crossing type as strake type wheel had the priority than half tracks and less sinkage and larger drawbar pull.
    5. Sinkage patterns of the half tracks were arc type ditches having the two peaks, one of them was found at the bottom of the rear wheel axle and the other was at the axle of the supporting wheel. Sinkage or drawbar pull of the half tracks would be more improved if these arc type patterns are more flat.
  • 木谷 〓
    1966 年 27 巻 4 号 p. 231-238
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The author tried to find out the reason of small tillage resistance of defomed rotary tillage machinery (like Spade Plow) by means of measuring resistance force, soil stress distribution in furrow slice and soil deformation.
    At first, the energy required to accelerate a furrow slice was calculated through the motion study of blade. It was found that the accelaration energy might exceed 20% of total tillage energy in the conventional machine.
    The cutting process is devided into two parts, namely, straight cutting and curved cutting. The cutting angle is so small that the resistance is quite low in the straight cutting process. The shearing action at the latter half of straight cutting process is bloked when the shear planes touch the bottom. Consequently, the resistance increases rapidly. In the process of curved cutting, shearing action without strong compression of furrow slice takes place. This contributes also to the small resistance of this tillage method.
  • 居垣 千尋, 山本 博昭
    1966 年 27 巻 4 号 p. 239-245
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    There are four kinds of method, of rotary tilling, i. e. Succesible plowing method, Alternated plowing method, Cycloidal plowing method and Rotational plowing method, as shown in Fig. 1, and five kinds of method of tilling the headland, i. e., Over-line turning method, Additioval plowing method (for A line), Additional plowing method (for B line), Combinative plowing method and Semi-followed plowing method, as shown in Fig. 2, which are the same methods as two-way plow's
    The formulas of the futile running distance that are calculated by combining these method are as follow:
    (1) Σ S+0=S⋅B/b
    (2) ΣS+2l⋅B/b=(S+2l)⋅B/b
    (3) ΣS+(S+2l)⋅2l/b+A=S⋅B/b+(S+2l)⋅2l/b+A
    (4) ΣS+B⋅2l/b+A=(S+2l)⋅B/b+A
    (5) ΣS+(l+πr/2)4l/b=1/b{(π+4)(B-2l)r+2l(2l+πr)}
    provided that {S=U in Cycloidal plowing method S=E in Rotational plowing method
    But when calculating the practical working efficiency, It is necessary to add the distances converted the time lossles which occur at gear change, and the variation of speed which occures at revesse.
    These formulas are shown in Tab. 1 and the specifications of the tractors used in the test are shown in Tab. 2. The efficiency curve of the each plowing method, When the area of the field is (20m)2-(100m)2. are shown in Fig. 3. From these results, altornated plowing method in the main area and Over-line turning method in the outside area indicate the highest efficiency respectively. Additional plowing method (for B line) and Combinative plowing mathod indicate the less efficiency than the former. Additional method (for A line) and Cycloidal method indicate comparatively low efficiency, but their efficiency may elevate a little if B line is divided suitably.
    The relation of plowing method and the area in order to have 80% of efficiency is shown in Tab. 4.
    The efficiency curves, generally tend to increase with the increase of the area, and this tendency is the most remarkable in Additional method (for B line).
    Considering the the slenderness rate of the field, the efficiencies of the three kinds of tractor increase with this rate as shown in Fig. 4.
  • 田原 虎次, 藍 房和, 須藤 允
    1966 年 27 巻 4 号 p. 246-249
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    We performed the experiment of stumping by the bulldozer in mulberry field.
    The results were as follows.
    Points of advantage.
    1. The stumping efficiency of this method was about four times as much as that of tractor.
    2. The work accuracy of this method was better than any others. The volume of pulling roots of a stump was vast, and the remains of roots in the soil were very little by this method.
    3. By this method, the deep tillage and the stumping could be done at the same time. The depth of the tillage was about 60cm.
    Points of disadvantage.
    1. The cleaning of stumps were troublesome, for it was difficult to clean the stumps by only human hand. Implements such as hoe or reaping hook should be used to clean them.
    2. The bulldozer might be easily damaged, than other methods, because of the frequency of clutching and changeing gear.
  • 川村 登, 滝川 博
    1966 年 27 巻 4 号 p. 250-254
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    Research descrived in this paper was conducted to investigate the threshing efficiency of rice and rice threshing power requirment of a fan type thresher. The fan type thresher is a radial-flow threshing apparatus, constructed of rotating metallic fan and its housing.
    Tests were conducted with two fans to determine the effect of the fan speed and the axial clearance upon the threshing efficiency, threshing loss, power requirment and the feeding and transport characteristics of grain and straw.
    With the increase of the threshing fan speed the threshing efficiency increases, but the damage of the paddy increases rappidly more than 2000 r.p.m. For the good feeding of straw to the thresher the suction air velocity must be more than 30m/sec. The percentages of perfectly threshed grain are 80-90%.
  • 竹内 竜三
    1966 年 27 巻 4 号 p. 255-260
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    To decide the air current of pneumatic separating path, the author applied Professor S. I. Pai's theory which found out phenomenon of the turbulent flow between two parallel plates, and decided that current of wind path was either turbulent flow or laminar flow, and in addition, drawn up the theoretical wind velocity curve.
    In consideration, the author applied variation value and mean value of mean wind velocity, discharge quantity and pressure at the Reynolds equation about three direction at standard middle part in wind path, and satisfied the Navier-Stokes equation in similarly. But these differential equation had many unknown value, and so, the author gave boundary condition and solved it. There are four method in deciding these equation, and we adopted the case that the velocity of upper and lower part of wind path was unequal, because this case was the most often in the winnower. In this case the author considered influence of coefficient of friction and also used the Laufer's experimental curve of turbulent flow. On the experimental machine, the wind velocity was found by convert of cordinate about not only the section of advance direction of wind but also the section of breadth direction of wind path, calculated minutely about the main or vice winnower. From the graph of these results, the mean velocity was gotton by measuring of area.
    For conclusion, [1] the author known either turbulent flow or laminar flow from wind velocity of two or three points, and it could be judged apart Reynolds number.[2] This application, applied to the condition of Poiseuilli's flow, was induced theoretically both distributing curve of wind velocity and equation, and was gotton about more complicated winnower's wind path than ordinary fluid machines.
  • 山下 律也, 笈田 昭
    1966 年 27 巻 4 号 p. 261-265
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The aspects of the moisture transfers between the dry rough rice and the wet rough rice during the storage, when the inequality of dryness was occured, were investigated in this report with the contact in layers and in mixture.
    The results are as follows:
    (1) A moisture gradient which occurs in case of the drying in layers is not vanished by means of leaving as it is.
    However, during the long time storage, wetting or drying by the atmospheric effect reaches to about 10cm deep.
    (2) when the dry rough rice contact with the wet rough rice in layers, the moisture transfer is observed.
    The quantity of the transferred depends on surrounding temperature, moisture difference between the dry and the wet rough rice, contact area and elapsed time after the contact. The quantity of the transferred moisture is represented with the linear equation, i. e.
    Q1=(a+bx) A (Ma-Mb) in early state, and by the constant exponential equation i. e. Q2=C1xdA (Ma-Mb) in later state, where Q1, Q2: the quantity of transferred moisture (10-4gr.), x: the elapsed time (hr.), A: the contact area(cm2), Ma: the dry basis moisture content of the wet material (%), Mb: the dry basis moisture content of the dry material (%), a, b, C1, α: the constant numbers which depend on surrounding temperature and elapsed time.
    (3) When the dry rough rice and the wet rough rice are contacted in mixture, the velocity of the transfer is faster than that in layers. The curve of the moisture transfer is changed by the moisture difference between the dry rough rice and the wet rough rice, and by the surrounding temperature; its empirical formula may be written as follows: Q3=C2xβ (D.Ma-E.Mb), Where Q3: the quantity of transferred moisture (gr.), D: the weigh tof the dried matter of the wet material(kg), E: the weight of the dried matter of the dry material(kg) (4) Although the moisture transfer between the dry rough rice and the wet rough rice is observed to some extent, both moisture contents do not agree with the mean moisture content because of the difference of the dry course and the wet course of the equilibrium moisture content. However, the higher the surrounding temperature, the closer the both curves.
  • 石原 昂, 西川 佳範
    1966 年 27 巻 4 号 p. 266
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 山下 律也
    1966 年 27 巻 4 号 p. 267-271
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 1966 年 27 巻 4 号 p. 272-278
    発行日: 1966/03/01
    公開日: 2010/04/30
    ジャーナル フリー
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