By using a model tractor, some tests were made on the slopes of various grades in order to know the size and shape of safety frames required for limiting the roll of 4 wheel tractors to 90 deg. The results obtained are as follows: (1) Safety frames whose width and height are respectively about 95% and 85% of the wheel bases of tractors are effective in case of travelling on the slope of 10 deg. (2) In case of the slope of 20 deg., slightly larger safety frames than those to that of 10 deg. are necessary. (3) On the slope of 30 deg., even if the width of the safety frames were equal to the wheelbases, one and half times the height of the wheelbases is required in order to limit the roll of tractors to 90 deg. (4) The relations between the height and the width of safety frames needed for safety operations on the slopes of various grades are shown in Fig, 5. (5) Times during side-overturning in case of travelling at the speeds of 2.0-3.0m/s are respectively 1.2-2.5sec., 0.8-2.0sec. and 0.4-1.2sec, on the slopes of 10 deg., 15 deg, and 25 deg, These data show that the escape of operators from, seats during side-overturning is probably impossible, even on the slope of angles less than 10 deg.
The dynamic side-overturning angles of 4 wheel tractors were measured by the method of model test, under the condition that the upper side wheel of tractor travelling toward the contour line got over a mountain shaped obstacle. The results obtained were as follows: (1) As regards the dynamic side-overturning of 4 wheel tractor, two methods of model tests were dealt with in this paper: one was the method whick described the dynamic property of rear tire as the restitution coefficient (Method A), the other was the method which described it as the spring constant (Method B). The similitude conditions of both methods are shown as eqs. (3) and (14). Both methods are considered to be useful, and yet Method A shows better accuracy than Method B. (2) It was revealed that the dynamic side-overturning angle of 4 wheel tractor was expressed as an empirical formula, eq. (24). Eq. (24) is αd=[1-q(H0/l)γV/√lg]αs2 where, αd: the dynamic side-overturning angle of 4 wheel tractor (°) αs2: the static side-overturning angle of 4 wheel tractor in second step (°) V: travel speed (m/s) H0: height of obstacle (m) l: wheel base (m) g: gravitational acceleration (m/s2) γ: constant determined by the elasticity of rear tire (cf. Fig. 10) q: constant determined by the elasticity of rear tire and tread (cf. Fig. 11) (3) Eq. (24) indicates that a 4 wheel tractor 1.9 ton weigh overturns sideway on the side slope of above 20°, under the condition: travel speed is, about 2m/s, and the obstacle is about 20cm in blight.
Non-weighted link analyses of nine binders and nine jidatsu-combines (Table 1) were performed to develope the design of simpler control devices. Results obtained might be summarized as follows: 1) The total frequency of links were higher in combines than in binders. As regards sub-jobs, the frequency was highest in start, and lowest in stop. (Table 2). 2) The frequency of operations in each organ (Table 3) was a little higher in limbs than in sense organs and highest in the right hand. The variation of frequency among investigated machi-nes was very small in sense organs and higher in the left hand than in the right. 3) The frequency of operations in each control device (Table 4) was highest in the traveling controls and lowest in the harvesting. But, the variation among machines was largest in the harvesting controls in binders and in the traveling controls in combines. The above variation was nearly nil in engine driving controls. 4) The frequncy of operations was chiefly affected by the number and the layout of equipped controls (Table 5), and had no connection with the engine power or the type of the machine. 5) The reduction of number of controls, including the adoption of such a cotrol as had plural functions, and the layout of controls following the routine sequence of operations were proposed to be effective for the simplificaion of operations.
The power requirement of tillage were measured by using the small tractor attached the simple inclined tillage tool at the front of rotary tilling device. The characteristcs of the combination tillage were summarized as follows (1) When a tine was mounted solely on the rotary shaft, the peak torque of rotary shaft in the combination tillage was about 0.3-0.4 times as large as that in the rotary tillage. (2) The toque of rotary shaft in the combination tillage was about 0.5 times as large as that in the rotary tillage. (3) When the frequency of the rotary ravolution is f0 c/s, the power spectral densities in 2 f0 and 15 f0 are greater than in other frequencies for the combination tillage, but that in 2 f0 and 12 f0 are greater than in other frequencies for the rotary tillage. (4) The effect of tilling methods on the distribution of the peak torque of rotary shaft could not be recognized in the tests, but the distribution increased when the tilling pitch was smaller on every conditions. (5) The rotary shaft power requirement in the combination tillage was equal to the sum of the drawbar horsepower of simple inclined tool and the horsepower of rotary shaft, and the power requirement was about 0.6 times as large as that in the rotary tillage.
The authors have determined the threshold limit value of local vibration of the vibrating agricultural machinery, in the previous paper. As this result showed the limit value curves went down at lower frequency (below 40-50Hz). To prove the cause, we have investigated the actual absorption and transmission of vibration in the human arm by taping piezo-electric-type transducer to the skin (near the bone) of the arm of an operator. The results obtained are as follows: 1) Steady state transmissibilities have approximately. a linear relationship with input ampltude, This is related to the damping and resilience properities of the bone and surrounding flesh. 2) Natural frequencies were obtained by bode diagram. The values were about 50, 25, and 15Hz at hand, radius and elbow joint. 3) The combination of the hand, radius, and elbow joint tends to prevent extensive high-frequency vibration propagation into the torso.
In this paper, the desirable operating method and the driving unit of the turning perforated pipe are discusssed theoretically and experimentally, from the viewpoint of uniform distibution of sprinkled water when it is used under the condition shown in Fig, 1. The results obtained are as follows: 1. For the sector-type driving unit shown in Fig. 4, the volume of sprinkled water directly below pipe is quite much and it decreases with an increment of distance toward the outer zone of sprinkling area. This distribution of sprinkled water can be obtained theoretically by the equation (7). 2. For the bar-type driving unit, almost uniform distribution of sprinkled water can be obtained in the sprinkled area which the range of turning angle is below 110°, however, in the range which the turning angle is more than that, the volume of sprinkled water becomes greatly much at outer zone of sprinkled area. The volume of sprinkled water can be determined approximately from the equation (11). 3. In the case of condition shown in Fig. 1 (a), the bar-type driving unit is better for obtaining the uniform distribution of sprinkled water, but for this driving unit the height of pipe and the pressure of water should be determined so that whole area can be covered when the range of turning angle of pipe is less than 110°. 4. For the case shown in Fig. 1 (b), in which the path is in the center of greenhouse and water is sprinkled both sides, using the perforated pipe with double row orifices and an included angle of 80°, most uniform distribution of sprinkled water can be obtained when the range of turning angle is nearly 45°. 5. The sprinkling intensity is apt to become excessive for both cases, because the sprinkling width in the direction perpendicular to the pipe is too narrow. If the distance between each orifice is 40cm, the sprinkling intensity is approximately 20 to 30mm/hr when (the diameters of orifices are 1mmφ and 1.5mmφ for the sprinkling width of 2m and 5m respectively) 6. Water pressure in this sprinkling device is. about 1.0 atm. Therefore, in the case of small scale irrigation and cheap water rate, the use of simplified water works or service water are desirable for saving the expense of power.
The natural frequencies of vibration for a portable rotary cutter with an electric motor were calculated by numerical calculation procedure using two shimplified models. The models are freely suspended and consist of two beams supported at 5 points with each other. In both models, the first beam has 5 mass on it and mass moment of inertia, gyromoment at each end. The second beam is uniform and connected with the first beam at 5 points, The programing and calculation by electronic computor are so easy that this numerical calculation procedure seems to be one of the convenient methods for calculation of natural and forced transverse vibration for double-beam system which have many mass, mass of inertia, springs of supprting points, The calculated secondary natural frequencies differed by about 5% from measured dear. As the models chosen are incomplete, it is desirable to improve them further for practical use.
The fluidized state of grains varied with the various factors. Many studies were performed to express the uniformity of fluidized bed. In this report, the fluidization index (I) was defined as follow. I=(mean deviation of pressure drop, mmAq) / (frequency of pressure fluctuation, cps) From experience, fluidization index has been associated with quality of fluidization, and for perfect fluidization the value of the index is equal to zero and increases as performance deteriorates. For agricultural products, such as rape seed, un-hulled rice and soy bean, the pattern of index was indicated in Fig. 6. In this figure, L0 is height of fixed bed, L is height of fluidized bed and D is diameter of fluidized vessel Obviously, the fluidization obtained by the felt distributor was better than by the wire screen distributor and the fluidization performance was influenced not only by the height of the bed but also by the vessel diameter.
This paper is to report the theoretical analysis and experimental studies concerning the flowing velocity of a single grain on the oscillating screen surface in circular motin. The idea was the same as the one used for the analysis of elliptical motion. The objective of this work was to check the validity of the theoretical equations. A point on the crank arm of the four-bar linkages was adopted to oscillate the screen in circular motion. Samples and measuring methods for the experiments were the same as described in the second report of this series. The motion of a single grain on the screen surface was analytically studied from the pictures of the stroboscope and the oscillograms of acceleration and phase angle. The conclusions were the following: 1) As the frequency and amplitude of the screen incressed, so did the mean velocity of grain. 2) In the case of counter-flow, the direction of relative motion of the single grain was positive, and the relative motion of grain on the screen surface changed from positive sliding motion to positive jumping motion. On the contrary, in the case of con-flow, it was negative, and the relative motion of the single grain on the screen surface changed from negative sliding motion to negative jumping motion. The motion of single grain after jumping was subjected to the phase of screen with respect to the landing. 3) Excepting the rolling motion of the single grain, the mean velocity of a single grain of the theoretical analysis agreed with the results acquired from experiments, and the rationality of the theoretical analysis was ascertained. This study may be applicable to the theory which will analyse flowing grain layer.
The authors studied the drying of unhulled rice the following point of view, that is, the rice consisted of hull and hulled rice which have different characteristies of drying. In adition they studied the drying characteristics of wheat, barley and soy beans for the relations of drying air temperature to the second critical moisture content. The drying constant (K) and the moisture diffusion coefficient (D), of each grain in the period of falling rate of drying were caluculated from the drying curves. 1) The first critical moisture content Mf1 of the grains which were taken to this study was recognized from the drying curves except for unhulled rice. Therefore, the apparent Mf1 of unhulled rice was evaluated from analyzing the relation of the drying curves of hull and hulled rice. The epuations giving relations Mf1 to absolute temperature of drying air were as follows; unhulled rice Muf1=9.12×10-1.81×10-1T hulled rice Mhf1=1.44×102-3.50×10-1T, hull Mcf1=3.48×10-1.70×10-2T, wheat Mwf1=1.81×102-4.70×10-1T, barley Mbf1=9.86×10-2.10×10-1T soy beans Msf1=3.38×102-8.50×10-1T, where Tis absolute temperature [°K] of drying air. 303≤T≤333 2) The equations of the second moistre content of the grains which were related to absolute temperatare of drying air were divided of iollowing three groups. The first was unhulld rice, the second was hulled rice, wheat, barley and soybeans, and the third was hull. The results were as follow; (1) Mf2=3.12×10-5.80×10-2T (2) Mf2=7.33×10-2.00×10-1T (3) Mf2=4.42×10-1.10×10-1T 3) Mf1 and Kf2 are the first and second falling rate of drying constant, respectively. The following equations related to absolute temperature of drying air were obtained; unhulled rice Kuf1=1.30×104exp-3.50×103/T Kuf2=2.80×10-2T-7.65×10-1 hulled rice Khf1=7.24×10exp-1.35×103/T Khf2=1.86×10-4.50×10-2 T hull Kcf1=1.51×1010exp-7.13×103/T Kcf1=9.60×10-3T-2.46 wheat Kwf1=9.05×105exp-4.61×103/T Kwf2=5.50×10-2 barley Kbf1=1.72×105exp-4.16×103/T Kbf2=5.50×10-2 Soy beans Ksf1=1.21×102exp-2.10×103/T Msf2=4.00×10-2 4) The ratio of the moisture diffusion coefficidnt (D1/D2) ranged in the following limits. where D1, D2 are the moisture diffusion coefficients in the period of first and second falling rates of drying, respectively. unhulled rice 1.4-2.4 hulled rice 2.0-3.0 hull 5.4-15.5 soy beans 2.5-4.4 wheat and barley 4.0-12.5
The authers constructed an apparatus for measuring the drying characteristics of a single grain of rough rice which was reported in the previous papar. The drying characteristics of a single grain of wheat at 10cm/s and 1cm/s air velocities was measured using the same apparatus but with a modified humidifier. 1. The temperature, the relative humidity and the air velocity were controlled within a range of (30-60) ±0.5°C, (40-80) ±1-2% R. H. (1-10) ±0.1cm/s, respectively. 2. The drying curves of wheat obtained were shown in Figs. 3 and 4. Both the constant rate period and the falling rate period were observed excepting the cases in which either the air temperature was 30°C or the relative humidity of the air was 80%. 3. The constant rate period was in the range of 5.5-22.4% d.b./h, except for 60°C, 0% R. H. 10cm/s air velocity (48.9% d. b./h). If the air temperature was the same, falling rate curves showed the same slope regardless of the humidity of the air. 4. At 30°C air temperature, there existed only the first falling rate period, but at air temperatures over 40°C, both the first and the second falling rate periods appeared. 5. The higher the temperature of the air, the influence of relative humidity upon the slope of falling rate curves was more pronounced, (Figs. 5 and 6) 6. The moisture content ratio was influenced both by the air temperature and the relative humidity, but the influence of relative humidity was little. (Figs. 7 and 8) 7. At a constant relative humidity, equilibrium moisture contents became almost the same in spite of differences in air temperature. 8. There was little influence observed of the air velocity around a single grain of wheat upon its drying characteristics.
Assuming that a gasoling engine was mounted on the cart which was used in a vinyl house, the concentration of CO gas in the air was measured in the vinyl house while an engine was operating. It was to know whether a gasoline engine could be used or not in a vinyl house, because of the CO concentration in the air. (1) The average concentration of CO in the air increased linearly with the operation time of the engine, when the vinyl house was not ventilated. (2) When the vinyl house was ventilated by fans and ducts, the average concentration of CO in the air was nearly constant regardless of ope-ration time. The value was lower considerably. (3) In the vinyl house whose floor area is more than about 1000m2, the average concentration of CO may be less than an allowable limit when the vinyl house is equipped with a ventilation arrangement. (4) To keep the concentration of CO around the engine less than the allowable limit may be difficult even though the ventilation is forced through the vinyl house. (5) It is not desirable to use a gasoline engine in a vinyl house. However, when circumstances require it, the suitable ventilation should be provided so that it meets the specification of the engine and the concentration of CO in the exhaust gas. And the cart mounting engine should be used only to carry product out of a vinyl house.
1) The thermal conductivity was measured of fresh and frozen pork, beef, pork fat and beef fat by the comparative method, in which the sample thermal conductivity was compared with the value of the standard glass plate having a known thermal conductivity. 2) The values obtained by the writers were given in Table 4 and compared with thermal conductivity that had been given by previous investigators. 3) The error of the current measurements was estimated to be less than ±2.0% for pork, which was the least, and ±4.9% for pork, which was the greatest. 5) The thermal conductivity of bacon, whose structure was shown in Fig. 3 was measured and compared with computed values. The discrepancies between them were 5.9% for fresh bacon and 11.4% for frozen one. 5) These results indicated that thermal conductivity values of meats and fats with two significant digits would be accurate enough for practical engineering calculation.
For the purpose of designing a container which would be used for transporting bulk Citrus Unshu the mechanical properties of Citrus Unshu were measured under the static or dead load, the quasi-static load and the impact load respectively, and the follwing results were obtained. (1) Under the quasi-static load which was produced by a plate and a plunger, the faster the loading rate, the larger the compressive strength. The compressive strength and energy required to rupture the Citrus Unshu (rupture energy) became lower in the stage of maturity after the first decade of November. At the loading rate of 50mm/min. when using the plate and plunger, the averege rupture energy was 9.80kg·cm and 1.87k·cm respectively. (2) Under the static load, the mechanics of the force-deformation relationship was a creep phenomenon. The acceptable static load in 60 to 70 hours without rupture was 5kg. The rupture energy under the static load was 7kg·cm. (3) To predict the creep phenomenon the best known rheological model which was composed of a slider in series 4-element was used. If the deformation of plastic flow expressed by a slider is 0.62cm, the parameters of this model run as follows; G1=5.17kg/cm, G2=10.0kg/cm, η2=79.6kg·h/cm and η3=1100kg·h/cm. (4) The larger the Citrus Unshu, the more durable against the falling impact. The rupture energy under the falling impact was 21.3kg·cm cmwhich was 3.05 times and 2.18 times as that under the static load and the quasi-static one respectively (5) To predict the maximum impact acceleration within the dropping height of 20cm, Hertz's theory for elastic body was available.