農業機械学会誌
Online ISSN : 1884-6025
Print ISSN : 0285-2543
ISSN-L : 0285-2543
29 巻 , 4 号
選択された号の論文の15件中1~15を表示しています
  • 増田 正三, 田中 孝, 山崎 稔
    1968 年 29 巻 4 号 p. 175-182
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    Fluctuations of transmitting torque and dynamic weight distribution of a tractor were measured when it was used under several transitional conditions.
    The conditions are to say sudden start and stop, sharp turning, running over uneven obstacles and heavy work with rotary tiller. Results obtained are as follows.
    1. Torque on clutch shaft
    The ratio of the measured maximum torque to the engine maximum torque (2.5kg⋅m/1800rpm) was obtained in each case (Tab. 2, 4, 5).
    In rotary tillage, the maximum ratio 2.5 was found in the vicinity of engine stop at the time of the most heavy work, but in normal tillage conditions, the torque frequency curves showed normal distribution and gave us some interesting informations (Tab. 7).
    2. Dynamic weight distribution
    Load factors are calculated on both front and rear wheel weight in each case (Tab. 2, 4, 6). Load factors amounted to 5.00 were obtained in the case of running over a ditch (Fig. 9, (c)).
  • 居垣 千尋
    1968 年 29 巻 4 号 p. 183-185
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    Fig. 2 shows the measuring results of the tractor weight that weigh to the 3 wheels which stand in a line at one side.
    In the figure, we can understand the fenomenon as followed. That is, the more increase the pressure of the idle wheel that is setting between the front and the rear wheels, the more decrease the weight of the rear wheel in inverse proportion to weight of the idler and, at the same time, the weight of the front wheel decreases slightly.
    We can understand this reason from the structure of the half-track.
    Next, in fig. 4 showing the relation of the ground contact pressure and the depth of the wheel sinking, the ground contact pressure of the front and the rear wheel as follows;
    Rear
    Dexta 0.15-0.2kg/cm2 0.1-0.2kg/cm2
    R-210 0.2-0.3kg/cm2 0.15-0.25kg/cm2
    Therefore, when the tightening spring is acting most effectivly, the ground contact pressure of the half-track and the front wheel keeps the well-balanced condition.
    But, the ground contact pressure of the medium size tractor, that may be regarded as main force in our country, is twice higher than that of the large size tractor.
    Therefore, the ground contact area of the medium size tractor must be twice, than the present one.
  • 田辺 一, 中尾 清治
    1968 年 29 巻 4 号 p. 186-193
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    A tractor keeping the inclined posture comes to take the weight difference on the each wheels, i.e. up hill and downhill wheels on the slope field or land and furrow wheels at the plowing time, andthen used to be compelled to have the deflection angle.
    Then, this paper deals with the effects for traction force, side force and running resistance, caused by the weight difference on the wheels having the deflection angle, and refer to the traction principle of the wheels. Test was divided into two sections as follows;
    (1) Pulling the test tractor with another one, the coefficient of the traction resistance does not change, but the coefficient of the side force decreases under the condition of heavier downhill or furrow wheel.
    (2) Driving by himself pulling some loads, the driving force of each wheels have larger differences for the heavier loads. It is helpful for the decrease of the deflection angle of the tractor running on the hill, because the side force comes to take the larger force caused by the induced turning moment directed to the upward and parallel to the ground surface by the difference of the driving force. But at that time, the traction force becomes decrease.
    We can now calculate mathematically the traction force, the driving force, the traction and running resistance and the side force, etc. by using the equatfons from (17) to (26).
    From our many test results, we can say that the weight difference on the wheels must be kept as less as possible for the purpose of the larger traction force.
  • 梅田 重夫, 毛利 建太郎
    1968 年 29 巻 4 号 p. 194-198
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The static characteristics of valves which supplied the pressure head varied from 0.1 to 15kg/cm2, were described in this report. The same valves which used in previous report were used.
    The discharge Q and lifting force P were measured at the various valve lift h under the various pressure head H.
    From these experimental data, the non-dimensional discharge q0, coefficient of discharge C, coefficient of resistance ζ which used in previous report and non-dimensional lifting force P0 were computed and expressed as functions of opening ratio h/d0., (d0: valve-port diameter)
    The following results were obtained.
    1) The non-dimensional discharge q0 increased linearly with the increase of opening ratio h/d0 in all valves.
    2) The coefficient of discharge C was the maximum value in the range of opening ratio h/d0=0.02-0.03, but not the maximum value in the ball valve.
    3) On the coefficient of resistance ζ, the ball valve was found the inflence of valve-port diameter.
    4) The non-dimensinal lifting force P0 was the minimum value at opening ratio h/d0=0.04 in the flat valve, and was the minimum value in the range of opening ratio h/d0=0.12-0.13 in the conical valve. On the ball valve, there was not the minimum value.
  • 川村 登, 並河 清, 池田 善郎
    1968 年 29 巻 4 号 p. 199-202
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    It is the object of this paper to show possibility and problems of the activation analysis technique for the study of spray deposits and diffusion and to discuss the properties of the spray deposit on the Knapsack type mist blower with this technique. We may summarize the results of our investigation as follows.
    1) We could acquire the technique of activation analysis and as the results of the experiment of spraying solution of manganese sulfate it was ascertained that e this activation analysis technique was very useful and speedy.
    2) The properties of spraying chemicals mist could be found to the extent of diffusion. At a short distance from the sprayer nozzle the amount of deposits on the front sampling paper was most and that on the back was least, however at a further distance than 15m from the nozzle the amount of deposits on the upper was most and those on the under, front, back and flank were almost equivalent.
    3) There was a very great difference between the amounts of deposits on the leaves among and outside the tree.
    4) It was shown that the activation analysis mentioned in this paper was useful for studying the properties of deposits of a ultra low volume spray by the airplane.
  • 竹内 龍三
    1968 年 29 巻 4 号 p. 203-208
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    (1) In the case that crop particles fell on the state of grid arrangements, and the stop-over interruption of behind stream in air flow path happened, the author analysed the equation of stream line using representation for two dimensional flow. As the results, the turbulence of flow lines was found.
    (2) These streams originated under the slow air velocity, pretty fast drop velocity and drop of weighty crops. The turbulence of flow lines was not always injurious influence on the selection of crops, rather, these flows had better excellent conveying velocities.
    (3) Next, as the results of analysis for the considerations of air velocity on three dimensional flows, the most exact and reliable value was air velocity of the center axis of rectangular flow path section.
    (4) The contour lines analytical method was used on this study, and the method was experimented in the practical grain separating path. If the density of contour lines decreased, and equal uniform air velocity happened, this method would be more effective.
  • 東条 衛, 岡村 太成
    1968 年 29 巻 4 号 p. 209-213
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The drying theory was applied to determine the effects of air temperature and initial moisture content on the drying character of soybean. The data were obtained under the various conditions; air temperatures from 30 to 61.5°C, air velocitiee from 0.6 to 1.7 (m/s), initial moisture contents from 25 to 43 (%) (D. B.), absolute humilities from 0.0055 to 0.0065 (kg H2O/kg dry air) and grain depth of 3cm.
    1) It was found that in the case of remoistened soybean, like other cereals, the results indicated the falling-rate drying equation was applicable to it.
    2) The straight lines were obtained, plotting free moisture ratios and drying times on semilogarithmic graph, and the calculated slopes of these lines are related to the drying constant K. This drying constant K has been given by the empirical formura,
    K=0.0419 Mo0.422×e0.00886t
    where Mo=initial moisture content % (D. B.)
    t=air temperature °C.
    3) Air velocity V has no important bearing on the drying constant, compared with the above-mentioned factors, Mo and t.
    4) The pressure drop per grain depth has been given by the empirical formura,
    ΔP/L=2.67V1.37(kg/m2⋅cm).
    where ΔP=pressure drop (kg/m2)
    L=grain depth (cm)
    V=air velocity (m/s).
  • 中馬 豊, 村田 敏, 武田 友四郎, 加藤 弘道, 渡辺 兼五
    1968 年 29 巻 4 号 p. 214-220
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The test equipment which was furnished with brushing mechanism for washing and applying wax in the process of citrus sorting was manifactured for trial. The extent of damage arisen from several operating conditions of the test equipment was investigated and the following results were obtained.
    1. As the result of examining the extent of external injury of summer orange with T. T. C. liquid, the extent of injury of summer orange was varied with the quality and the length of the hair of brushes used for washing.
    In the order of extent (1) horse hair, (2) toron, (3) mixed hair (man hair and horse hair) (4) sponge, (5) man hair, (6) towel (Table 1)
    2. Variation of Resperating intensity of summer orange after brushihng varied with quality of hair of brush and brushing time.
    The severer the injury of summer oranges, the more vigorous the breathing exercise of them. Thirty seconds stimulus by toron brush was severer than thirty minutes stimulus by vibration of 0.7 G acceleration. (Fig. 3)
    3. Back-wardly, conjecturing the extent of external injury inflicted by brush hair, from the decay conditions of summer orange in storage, the order of hair which inflicted injury were as follows.
    (1) horse hair, toron, mixed hair (2) man hair (3) non-treatment. (Fig. 4)
    4. The loss in weight of summer orange in storage was influenced by quality and length of hair of brush.
    The severer the injury of orange inflicted by brush, the heavier the loss in weight; i. e. the ranking of loss in weight was consistent with the result of judging the extent of injury by T. T. C. (Fig. 5)
    5. It was not distinguished that the brushing affected to the contraction of summer orange. (Fig. 6)
    6. The summer orange washed by brush was more softened than non-treatment one.
    The severer the external injury of orange, the more remarkable this tendency. (Fig. 7)
    7. It was considered that the jumping height of summer orange upon the brush affected to the extent of injury. Next terms were conditions of lowering the jumping height: (1) Low R. P. M. of brush
    (2) Spacious clearance between brushes (3) Nearly spherical summer orange (4) Small size and light weight of orange,
    Practically, if selection about the former (1) and (2) was done sufficiently, jumping height of orande in brushing lowers and consequently injury lessens. (Fig. 8)
    8. On the parts on surface of orange that wounded by brush (which was distinguished by T. T. C.), sometime later, the green mold luxuriated as same as Saturns rings.
    In other wards, the brush was medium of mold, therfore the germicide should necessarily be considered at the same time. (Photo. 4)
  • 中馬 豊, 村田 敏
    1968 年 29 巻 4 号 p. 221-224
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The half-cooling time of the mass-average temperature of the spherical fruits and vegetables are caluculated as the solution of the following equation by electronic computer in the range of cooling-air velocity between 2.0m/sec and 5.0m/sec, and in the range of diameter of fruits and vegetables between 1.0cm and 30.0cm (Table 1).
    0.5=∑
    n=16 (ah) e-καn2THALF/(aαn)2((aαn)2+(ah) (ah-1)) (1)
    where
    Thalf: half-cooling time, κ: thermal diffusivity of fruits and vegetables, a: radius of spherical fruits and vegetables, h=H/Kp, H: surface heat transfer coefficient, Kp: thermal conductivity of fruits and vegetables, αn: the n th roots of
    (aα)cot(aα)+ah-1=0 (2)
    The surface heat transfer coefficients H are caluculated with the following empirical formula by McAdams:
    HD/Kf=0.33(wD/ν)0.6 (3)
    where
    w: velocity of cooling air, D=diameter of spherical fruits and vegetables, Kf: thermal conductivity of cooling air,
    ν: kinematic viscosity of cooling air.
    The thermal property of the air and the fruits and vegetables are assumed that K=5.0×10-4m2/hr, Kp=0.36Kcal/mh°C, Kf=0.0207Kcal/mh°C (at 0°C), ν=0.138×10-4m2/sec (at 0°C).
    The following approximate formula are derived on the assumption that the terms of the series of the equation (1) after the first may be neglected, and the half-cooling time are also caluculated with the formula (Table 2).
    The cooling time can be estimated accurately by the following formula with the half-cooling time in Table (1) in the range that the value of Table (1) is equal to that of Table (2):
    t=3.322 THALF log10((Vpo-Vf)/(v-Vf)) (4)
    where
    t: cooling time (hr), Vpo: initial temperature of fruits and vegetables, Vf: temperature of air, v: final mass average temperature of fruits and vegetables.
  • 洪 隆宣, 川村 登
    1968 年 29 巻 4 号 p. 225-230
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
    The pressure acted upon each portion of compression chamber was investigated, when the plant was compressed. And dynamic characteristics of solidity was studied rheologically by the experiment of stress relaxation.
    1) The difference between piston pressure and base pressure, which is theoretically equal to supporting pressure of cylinder, is little as the plant is feeble. Theoretical supporting pressure is nearly equal to experimental value only in case of the feeble plant.
    2) When the plant of high moisture content (about 29%) was compressed, there are two sorts of plants which increase or decrease in supporting pressure of cylinder. It seems that water extruded from Italian ryegrass acts as lubrication and that from orchard grass acts as adhesion.
    3) Relaxation modulus of compressed plants has the linear portion against the logarithm of relaxation time.
    4) Relaxation spectrum became little when compression speed, sample quantity, moisture content and cut length were little, and when materials were stuffed irregularly.
    5) When the solidity was good, relaxation spectrum and relaxation time became generally little.
    6) Sample quantity and cut length must be equal in order to judge the solidity by means of relaxation spectrum.
    7) Relaxation spectrum perpendicular to the axis of cylinder is little.
    8) Stress relaxation of stiff materials occurs in part where materials touch on the inner wall of cylinder, but that of feeble materials occurs only in inner part of materials.
    9) The method of using box type-relaxation spectrum is useful to investigate the behaviour of visco elasticity of compressed plants.
  • 梅田 重夫, 滝川 博
    1968 年 29 巻 4 号 p. 231-232
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 石原 〓, 西川 佳範
    1968 年 29 巻 4 号 p. 233-234
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 田中 孝
    1968 年 29 巻 4 号 p. 235-240
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 真鍋 常秋
    1968 年 29 巻 4 号 p. 241-244
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
  • 1968 年 29 巻 4 号 p. 245-248
    発行日: 1968/03/01
    公開日: 2010/04/30
    ジャーナル フリー
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