農業機械学会誌
Online ISSN : 1884-6025
Print ISSN : 0285-2543
ISSN-L : 0285-2543
35 巻 , 2 号
選択された号の論文の16件中1~16を表示しています
  • 遠藤 俊三, 西村 功, 笹尾 彰
    1973 年 35 巻 2 号 p. 128-133
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The tractor vibrations are subject to the influence of very complicated sources-engine, road surface, tilling device etc. We obtained the influence degree of the sources by the spectrum analysis.
    (1) The tractor vibrations suffered the largest influence from the engine.
    (2) Vertical and transverse vibrations resulted in higher acceleration at the chassis, but vertical and longitudinal vibrations resulted in higher acceleration at the seat.
    (3) The ratio of the seat power spectral density (P. S. D) to the chassis P. S. D under 100Hz range resulted as follows,
    |A(f)|≈1.0 for vertical diretion
    |A(f)|≤0.5 for transverse direction
    1.0≤|A(f)≤2.5 for longitudina direction
    (4) as for the influence of road surface, only the 1st order of input frequency had a great infiuence on the vibrations of vertical and longitudinal directions, and the influence of the 2nd and 3rd order for transverse direction was large.
  • 伊藤 信孝
    1973 年 35 巻 2 号 p. 134-142
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    In this paper, the stress distribution under a rigid wheel with sinkage is discussed based on the results obtained by photoelastic experiment.
    Three different shapes of photoelastic material under rigid wheel were prepared and vertical and tangential forces were acted on the rigid wheel, one was acted on the axle and another on the periphery of the rigid wheel.
    Prior to the experiment, a theoretical consideration was introduced assuming a stress distribution pattern under rigid wheel consists of two zones.
    From the results of photoelastic experiment it was found that the stress distribution under rigid wheel driven with some sinkage mostly consists of two zones compressing zone and bulldozing one. Compressing zone produces thrust force to the drive wheel, whilst bulldozing zone acts as resist to the travel of the wheel. The difference between the thrust force produced from the compressing zone under the driving wheel and the resisting force from the bulldozing zone may make the effective thrust force of drive wheel.
    All unknown factors were determined based on the following procedure.
    (1) stress distribution was drawn
    (2) compressing and bulldozing zones were determined
    (3) Summation of external forces, vertical and tangential forces were shared by the ratio of both areas
    (4) the center of gravity of each zone was determined
    (5) the magnitude of resultant of reaction forces derived from the both zones was obtained
    (6) other unknown factors such as components of the resultant were determined by procedure (5)
    The calculated results from the above procedure were well valid in comparison to the theoretical approach.
  • 梅田 重夫, 池田 敏夫
    1973 年 35 巻 2 号 p. 143-150
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The consideration and improvement of the hydraulic control system on the rotary tillage in previous report are performed using an analog computer.
    As a result of the stability analysis of this system, the limit cycle is prevented when the amplified link ratio 1 is small. The control valve with on-off action deteriorates the stability and deviation of system, but these characteristics are also improved when the link ratio is small.
    Another method to get the good stability and deviation is to decrease the oil flow into the operating cylinder. But in this case, the response of system becomes more slowly.
  • 芝野 保徳
    1973 年 35 巻 2 号 p. 151-156,162
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The estimated fatigue life and the calculated diameter of the main tilling transmisson shaft on the rotary and the combination tillage were analyzed by using the all peaks count method, the range count method and the full wave method for complex stresses. The conclusions were the following:
    (1) For the fatigue life predictions of the tilling transmission shafting, the all peaks count method gave the longest estimated fatigue life and the range method gave the shortest of it.
    (2) And then, for the frequency distribution analysis of working stresses of the tilling transission shafting, the full wave method gave the best predictions.
    (3) It was possible that the shaft diameters of the tilling transmission shafting in the combination tillage were 0.62-0.73 times as large as that in the rotary tillage.
  • 芝野 保徳
    1973 年 35 巻 2 号 p. 157-162
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The power requirement of tillage was measured by using the small tractor attached the drawn tillage tool at the rear-side of rotary tilling device, and sometime varying depth of tool and tine respectively.
    The characteristics of the combination tillage were summarized as follows;
    (1) The tilling pitch in case of the combination tillage decreased as the travel speed of the tractor decreased with an increase of the draft resistance of the drawn tillage tool.
    (2) Therefore, the torque of rotor shaft of the combination tillage was 0.75-0.85 times as large as that in case of the rotary tillage.
    (3) In the combination tillage, the power of driving shaft increased with an increase of the dnaft resistance of the drawn tillage tool, while the power of rotor shaft decreased with an decrease due to the tilling pitch. Therefore, the total power consumption in the combination tillage was 0.9-0.95 times as large as that in case of the rotary tillage.
    (4) The combination tillage was superior on the specific work done.
  • 古池 寿夫, 岡田 芳一, 永田 雅輝
    1973 年 35 巻 2 号 p. 163-169
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    Authors changed the number of tines from 16 to 32 and the speed of rotary shaft from low or medium to high in a rotary tiller of 55cm width.
    The tests were carried out on the paddy fields after harvestig at Miyazaki, Okayama and Miyakonojo. These tests have been done in connection with the increment of cut (number of tines, speed of rotary shaft, foward speed), tilling depth, number of tillings, and moisture content of soils.
    The result was as follows;
    (1) Between 32 tines and 16 tines in the same lead, the pulverizing action of 32 tines was larger than 16 tines, and the coefficient of surface area of 32 tines was larger than 16 tines when the moisture content of soil was little. But when the moisture content of soil was high, the soil pulverizing ratiounder 1cm of 32 tines was smaller and the rat ioabove 4cm was almost same compared with 16 tines.
    (2) Generally, the action of pulverizing of small increment of cut was excellent when the moisture content of soil was little, but not so good when the moisture content was high.
    (3) Pulverizing action in tilling depth of 5cm was larger than in the depth of 10cm at the same increment cut.
    (4) Power repuirment of the rotary shaft at speed of 0.4m/s was frequently over 5 ps and less than 0.5 ps at 0.2m/s.
    (5) Tilling volume per horsepowerhour of 32 tines showed 10-20% decrease compared with that of 16 tines.
    (6) Pulverizing action was excellent when the increment of cut of second tilling was small in double tilling.
  • 古池 寿夫, 岡田 芳一, 永田 雅輝
    1973 年 35 巻 2 号 p. 170-177
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    We carried out the tests to improve the performance of stubble disposing of rotary tiller. The tests have been done on the paddy fields at Miyazaki, Okayama and Miyakonojo after harvesting in connection with the increment of cut (number of tines, speed of rotary shaft, foward speed), tilling depth, number of tillings, soil moisture content.
    The results was as follows;
    (1) Between 32 tines and 16 tines in the same lead, remain ratio of all stubbles of former was smaller than that of latter at every districts.
    (2) Remain ratio of all stubbles of tilling depty of 10cm was smaller than that of the depth of 5cm in the same increment of cut.
    (3) Many small stubbles were scattered on the field when the moisture content of soil was little.
    (4) Remain ratio of weed of 32 tines was a little smaller than that of 16 tines. Remain ratio of weed of the depth of 10cm was smaller than that of the depth 5cm in the same increment of cut.
    (5) Germination percentage of rye of the largest increment of cut (16 tines, low shaft speed, 0.4m/s) was small and that of the smallest increment of cut (32 tines, high shaft speed, 0.2m/s) was also a little small.
    (6) There were little stalkes on the field.
    (7) When the depth of the first tilling was 5cm, the increment of cut was small and the depth of the second tilling was 10cm, both the remain ratio of all stubbles and the remain ratio of weed were small.
    (8) Tilling accuracy of the smallest or medium increment of cut in single tilling was very excellent except in the case of high moisture content of soil.
  • 児玉 義彦, 飯本 光雄, 山中 捷一郎
    1973 年 35 巻 2 号 p. 178-183
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    In order to investigate the spray distribution from boom nozzle, the theoretical formula based upon Bernoulli's theorem was made, and the calculated values from the theoretical formula were compared with the values resulted from experiment. The results were as follows;
    1. The relationship between Qi-1 and Qi on the discharge of nozzle is as follows (Fig. 1):
    Qi/Qi-1=√(Ca/F)2[(Q′i-1 Qi-1)2(-ξ-2λli/d)/+2(Q′i-1 Qi-1)(2λli/d+η)-(2λli/d+η)]+1
    2. The difference between the experimental results and the calculated results, were not large.
    3. The spray capacities of all individual nozzles were almost the same.
  • 藤木 徳実
    1973 年 35 巻 2 号 p. 184-191
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The movement of fluid in p. d. heads (an abbreviation of perforated dust heads) can be thought as a single-dimensional flow. Based on the fact that the change of static pressure in p. d. heads is derived from the frictional head loss by the pipe wall and from branching flow rate, the theory of predicting the static pressure was described in a formula. Here, Darcy & Weisbach's formula was introduced to calculate the frictional head loss.
    (1) Theory of pressure gradients for incompressible flow.
    The pressure variation (PI-P0) in an arbitrary division which has perforations and a length of L can be calculated from the following formula.
    PI-P0γa=fL/24gM(VI2+VIV0+V02)-K/g(VI2-V02)…(1)
    Where, VI and V0 are mean air velocities at the upper reaches and at the lower reaches, respectively. f=friction coefficient, g=acceleration of gravity, M=hydraulic diameter. The formula may be transformed as the next.
    PI-P0a=1/3{fLVI2/D⋅2g+fLVIV0/D⋅2g+fLV02/D⋅2g}-2K{VI2/2g-V02/2g}
    Consequently, the change of static pressure between the both reaches equal to the sum of the arithmetic mean of frictional head losses which calculated with VI2, V02 and VIV0 and the change of the kinetic energy multiplied by a constant (-2K).
    If VI and V0 equal to V, the formulae returns to Darcy & Weisbach's formula by substituting V=VI=V0. Therefore the formula can be applied to arbitrary division of pipes and ducts with branch or without branch.
    (2) Theory of pressure gradients for compressible flow.
    Considering the aerial compressibility between the upper and the lower reaches, the change of static pressure can be calculated from the following formula.
    PI-P0=fL(P+P0)/24gMRT(VI2+VIV0+V02)-K(P+P0/gRT)(VI2-V02)/1-fL/24gMRT(3VI2+2VIV0+V02)+KVI2/gRT
    This is a quotient of the precding formula (1) devided by the denominator. And if the denominator approximate to 1, the formula (2) is the same as the former. Where, P=atmospheric pressure, R=gas constant, T=absolute temperature.
  • 1973 年 35 巻 2 号 p. 191
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 岩尾 俊男, 田辺 一
    1973 年 35 巻 2 号 p. 192-199
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The object of this study is to find out the characteristics of stratification for the undersize grain in a batch sieving process, using a ro-tap shaker.
    The physical properties of grain related to stratification were the difference of size, specific gravity and characteristics of grain surface. River sand and soy bean of uniform size were used as the materials of bed.
    The results were as follows:
    1) The pressure applied to the bottom of soy bean bed gradually increased with the increase of the height of bed.
    2) The acceleration of soy-bean in the bed was large at the under part and small at the upper part.
    3) The time which the undersize grain pass through the bed increased with the increase of the grain.
    When the ratio of sizes of undersize grains to those of oversize grains were nearly equal, using various sizes of undersize and oversize grains, the time to pass were approximately equal.
    4) The relationship between the time to pass through the bed and the height of bed is given by the exponential function in the following.
    t=aebx
    Where, t: time to pass through the bed of undersize grain, x: height of bed, a, b: constant.
    In the case of the same kind of undersize and oversize grain, the length of screen for the continuous screening is given by the following equation.
    L=Vaex0.1934 (d/D×100)0.2831
    Where, D: grain size of bed, d: undersize grain size L: length of screen, V: flowing velocity of grain.
    5) The velocity to pass through the bed increased with the increase of the difference of specific gravity among grains. And it was slightly decreased with the increase of the difference of the coefficient of friction among grains.
    6) The velocity of grain passing through the bed increased with the increase of the frequency.
    7) In the case of separating of farm products, as for the physical property of grain to pass through the bed, it can be considered that the ratio of the size of undersize grain to that of the oversize grain is the principal facter, and the specific gravity and coefficient of friction of grain are less significant.
  • 小森 盛
    1973 年 35 巻 2 号 p. 200-206
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
    The energy requirments for tilling or padling work can be obtained by summing up the each energy requirment for the unit operation costitute the work.
    Topographical conditions of the field and the operation will act upon the energy requirment very strngly.
    The energy requirment per 10a for tilling work by rotark tiller was 596.3 Cal at plain field, 658.9 Cal at piedmont field, and 879.0 cal at mountainous field respectively.
    E/10a for paddling work by rotary tiller was 499.6 Cal at plain field, 646.6 Cal at piedmont field, and 654.4 Cal at mountainous field.
    E/10a for tilling work at piedmont field by larg tractor with rotary was 264.4 Cal and E/10 a by medium size tractor was 333.4 Cal.
    E/10a for puddling work at plain field by larg tractor with rotary (3 labourors) was 198.0 Cal, and by medium size tractor (2 labourors) was 186.8 Cal.
  • 並河 清, 川村 登, 行枝 亮, 藤浦 建史
    1973 年 35 巻 2 号 p. 207-211
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 土井 淳多
    1973 年 35 巻 2 号 p. 212-217
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 1973 年 35 巻 2 号 p. 218-219
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 1973 年 35 巻 2 号 p. 221-223
    発行日: 1973/09/01
    公開日: 2010/04/30
    ジャーナル フリー
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