As a method for the addition of water or ethanol into gasoline or kerosene for agricultural electric ignition engines, pulverization and vapourization method was studied, and the following results were obtained.
(i) As the result of theoretical calculation of vapourizing speed constants for fuels and added materials, the constants of water and ethanol were turned out very small in comparison with the constats of gasoline and ethanol. Thus, pulverization and vapourization method is considered to be effective for the addition of water and ethanol.
(ii) When operating conditions of engine is the same, the weight of inhaled air does not change by air/fuel ratio and the quantity of added water or ethanol
(iii) When water is simply added to fuel, engine can not be operated smoothly, but by pulverization and vapourization of the mixture, engine is smoothly operated upto 70%(wt) water addition. The suitable quantity of water addition for the decreasing of NO_x, without lowering engine performance, is thought to be about 50%(wt) of gasoline. In this case, engine performance is decreased a little compared with the case of pulverized and vapourized gasoline, but far better than that of ordinary supply of gasoline, and No_x is decreased up to 80%.
(iv) Simple addition of ethanol into gasoline lowers engine output and thermal efficiency, but they were improved by pulverization and vapourization. NO_x is not decreased by ethanol addition, but increased by pulverization and vapourization. However, when the combination of heating quantity and ignition timing are adjusted to get maximum output, NO_x is decreased to almost the same as in the case of simple ethanol addition.

View full abstract

In factors influencing the power performances of an air- and charge-cooled Wankel rotary engine for general use, principal factors controlling the quantity of blow-by gases past the sealing devices out of the combustion chamber are 1) the clearance of gas seals, 2) the stiffness of gas seal springs, and 3) other design measures such as adopting the dual side seals for a single, appending a seal ring around the center hole of a rotor as described later.
Experimental and theoretical investigations were done on the relationship between these factors and the power performance or the volumetric efficiency of proto type engines. Summary of results is as follows: -
(1) In the statical measuring experiments of the quantity of escape gases, which were performed on condition that the rotor was stopped at the rotating position of 90 degree from the top dead center, the maximum quantity in escape gases per unit contact length of gas seals was the gases past the clearance of the apex seal, but the maximum absolute quatity in escape gases was the gases past the side seal clearance (Fig. 1, 2, 3).
(2) In firing states, however, the clearance δ_c between the corner seal and the rotor slot has the greatest effects upon the power output, followed by 1) the clearance δ_al, which is the size difference between the length of the apex seal and the width of a rotor housing, i. e. the distance between both side housings, and 2) the clearance δ_at between the apex seal and its slot (Fig. 6, 7). The effect of 1) the clearance δ_st between the side seal and its groove, and of 2) the butt celarance δ_sl between the side seal and the corner seal on the power output is negligibly small.
(3) The design measures such as 1) adopting double side seals for a single, 2) appending a seal ring, i. e. an annular cast iron ring loaded by an O-ring which also acts as a secondary seal, in addition to the side seal, are effective for improving the volumetric efficiency η_v, since these measures reduce the quantity of blow-by gases toward the rotor center hole.
However, in the high speed range of more than 4000rpm, such design measures can not be adopted as the loss of power output increases rapidly (Fig. 4, 5).
(4) The gas seal clearances, which exert the greatest influence on the power performances, have to be made as small as possible taking consideration of the mutual relationship between machining accuracy and its cost (Table. 1).
(5) Though neccessary primarily for an engine starting aid, the gas seal springs are little neccessary after starting, since they are normally actuated by the combustion gas pressure. The stiffness of gas seal springs, therefore, should be made adegately soft (Table. 1, 2).

View full abstract

In this paper, the design theories for the single-edged curve of Japanese rotary blades were obtained by the geometrical analysis.
1) Shapes of blade cross-sections of the lengthwise blades were observed, and it was conjectured that the decreasing tillage resistance of single-edged blades are more advantageous than double-edged ones.
2) The cross-section of lengthwise blade is usually designed on the radius direction of the edged curve, the actual shape of blade cross-section in the soil exists on the trochoid locus curve of the blade motion.
3) The forming process of lengthwise blade portion was observed in the production-line of Japanese rotary blades. The result was that the blade cross-section in the radius direction of edged curve might be of uniform thickness with single-edge which gives the decreasing resistance, due to reasonable relief angle between the blade and the material to be cut.
4) The theoretical analysis for examining angle-operations of blade which has a round cornered edge with radius r, was presented. The calculated equations of actual cutting angle ε₁ and actual relief φ of the lengthwise are obtained as follows:
ε₁=tan^-1[2L₁tan(ε₀/2)-(t¹-t²)tan(β+α-90){(M-r)tan(ε₀/2)+r}/2L₁[(M-r)tan(ε₀/2)+r]√1+tan²(β+α-90)]
φ=tan^-1{(t¹-t²)tan(β+α-90)/2L₁√1+tan²(β+α-90)}
5) The changing range of angle β and the actual cutting angle ε₁ at the lengthgwise blade with single-edge are presented by the graphs, shown in Fig. 7. These graphs are used to obtain the relationships between the actual cutting angle with tillage conditions and design factors, for designing the lengthwise blades of Japanese rotary blades.

View full abstract

In order to clarify the deformation, stress and failure pattern of the soil a small bin test device for Moirè method and soil stress meters were designed and constructed. From a series of experiments using these devices the following results were obtained.
1) The Moirè method made it possible to analyze the soil deformation under orthogonal cutting.
2) Neither the cutting conditions nor the soil conditions affected the direction of the principal strain. The cutting conditions gave effects on the soil deformation range, and soil conditions affected the magnitude of the principal strain of the soil.
3) Neither the cutting conditions nor the soil conditions affected the direction of the principal stress. Those conditions gave cosiderable effects on the magnitude of the principal stress as well as the stress distribution along the shear plane.
4) Vibratory tillage reduced the soil stress on the shear plane as compared to the non-vibratory tillage. This resulted in the smaller shearing force.
5) The shearing pitch increased proportionally to the cutting depth and soil hardness within the moisture range of 22%-27%.
6) Backward motion of the blade caused cracks near the edge point of the blade which reduced the shearing force.

View full abstract

It is indispensable for the automatization of field machine to detect the end of field. This may be solved, in paddy field, by detecting levee. The infrared opto-electric sensor of reflection type which is attached on the head of a vehile in downward reclined posture senses the reflection from side slope of levee. Output voltage of the sensor is processed by a micro processor. The process method is as follows. The output voltage is sampled at certin interval(V_n) and the difference V_n-V_n-1 is calculated. Thd index I_n=V_n·|V_n-V_n-1| and the the mean I_n=(I_n+I_n-1)/2 are obtained, and In is one after another compared with the level k·I_n (k; coefficient). If I_n exceeds the level, a command is signalled to stop the vehicle.
In this paper, above-mentioned method was presented together with the output voltage changes of sensor scanning model field and levees of various cross sections and practical field. The results of field tests with the trial detecting device mounted on a vehicle were discussed.
The region of sensor heights and angles that levee could be detected was indicated by three curved borders in the represented graph taking height and angle in both axes. Three borders are defined by the relation of sensor height or angle to the dimension of levee cross section, and the characteristics of the sensor. The stop positions in the same combination of sensorr height and angle were measured on 9 types of levee. The combination that minimized the standard deviation of measured values was 30cm in sensor height and 30deg in sensor angle or 40cm and 45deg. If the sensor is set in that combinatin, the stop position of the vehicle will not differ so much for any type of levee.

View full abstract

An accurate seed metering system for raw seeds was designed which consisted of a bowl type feeder for seed feeding and a circuit for intermittent drive of the feeder to control the timing of seed separation on a track.
The following results were obtained.
1. The conveying of seeds on the track were controlled by an electromagnetic device, and the seeds were continuously conveyed in a row on the track.
2. In an accurate metering system, the metering time was set so that it might correspond to the conveying time interval under the constant conditions.
3. Laboratory tests on the tape for a tape seeder or the belt with an adhesion tape indicated that the metering system metered seeds with less errors than either a seed plate or a belt cell types.

View full abstract

The interrelationships between extension, compression and shearing characteristics of rice seedling mats were investigated, and it became clear that those had mutual relations each other. Therefore, mechanical properties of mats may be qualitatively grasped by knowing one of the factors for example, extension strength. This seems to give some sugges tions about measurement of the mechanical properties of mats and application of results.
All data of extension strength as a representative value were reexamined and mechanical properties were arranged. The extension strength obtained in this study ranged from 0.01 to 0.22kgf/cm² (0.98 to 21.56kPa). This in which range nearly overlapped to the one of actual rice seedling mats raising in the farms. It became clear that not only bed soil and the weight of root but also the strength of each root and root distribution remarkably affected the extension strength.
Furthermore, some qualitative considerations were given to the relationship between anisotropy and inner structure of mats i. e. condition of roots, to the representation of elastic, plastic and viscostic behaviours by a mechanical model, and to the failure criteria.
However, mechanical properties of mats was only understood comprehensively because of complication and difficulty.

View full abstract

In the previous report, the effects of the set of rollers design and material in a hay conditioning process was investigated in laboratory scale tests. In this paper, the crimping rollers and the crushing rollers in the previous roller mechanism was compared in the practical condition. The loading force of the rollers was 25-75kg while the speed was 250-850rpm.
Materials were fed into the conditioning rollers in practical condition
The drying tests of the samples through the conditioning rollers were the same as the previous way. Freshly cut Orchard grass, Red clover and Alfalfa were used in the tests.
The results were as follows;
1) The drying curve of the grass from the initial to a given moisture level was expressed by a variant exponential equation (Ae^-kθ) in the same as the previous report. After this moisture level the drying rate changed slowly.
The larger the drying constant (K) the faster the drying rate of grass. The drying constants of the treated grass by the rollers were larger than that of untreated grass.
2) The drying constants of the grass and the untreated grass were as in Table 2.
The crimping rollers provided a higher drying rate than that of the crushing rollers for Orchard grass (first and second cut) and Red clover, while the crushing rollers provided a higher drying rate for Alfalfa.
3) The drying rates of treated grass were not affected by the feeding rate of grass through the rollers. The drying rate were only slightly affected by the loading force of the rollers in crushing rollers and by the speed of the rollers in crimping rollers.
4) The crimping rollers had a higher clipping in Orchard grass and Alfalfa than the crushing rollers, while the crushing rollers had a higher clipping than the crimping rollers in Red clover.
The clipping of Alfalfa was higher than the other forage crops in the both types of rollers.

View full abstract

Pneumatic conveying characteristics of cereal grains was examined with extra low pressure ejector, which had been investigated on rice hull in our previous reports.
The experimental results were as follows,
1. Conveying the grains required larger quantity of energy P_s with respect to conveying rate W than conveying the rice hull. The fact might come from the reasons that the terminal velocity vt of the grain was larger than that of rice hull and the average velocity v of the air in the tube became greater for the grain than for rice hull. By comparison of wheat and unhulled rice, smoothness of the kernel seemed to relate to this result.
2. As for energy efficiency η at the ejector part, conveying the rice hull was particularly inferior to conveying the unhulled rice. The result was caused by the fact that the values l_best of conveying the rice hull were remarkably larger than those of conveying the unhulled rice.
3. The values of conveying effectiveness W/P_f which summed up those of the ejector part and conveying tube part were almost same in every our experiments. Consequently extra low pressure ejector was practically available to pneumatic conveying of cereal grains if the values of lift head H and conveying distance L were smaller than those of this study.
4. If the static pressure h_f at the nozzle part was increased, effective pressure h₂ and conveying rate W were increased. But the increased quantity of conveying rate was quite small. Therefore energy efficiecny η of the ejector was decreased remarkably and conveying effectiveness W/P_s resulted in very small value. These results showed that this system was favorable to the conveying which was performed under the condition of low static pressure.

View full abstract

The objective of this study was to estimate the effect of temperature, ethylen and ventilation in artificial banana ripening. The experiments were conducted under combined conditions of these three factors using about 12kg of green mature banana. Sugar content of banana pulp was employed as a measure for the estimation of ripening Obtained data of sugar contents were used for the analysis of variance to examine the effects of each factor.
The results were as follows.
1) Effects of ethylene on ripening appaered as interactions with temperature in three and five-day of ripening and as main effect in seven-day of ripening.
2) In banana ripening with ethylene, temperature had remarkable main effects in three, five and seven-day of ripening. The difference of effect between the ethylene concentration of 100ppm and both 500 and 1000ppm was recognized only in five-day of ripening. Therefore, temperature was considered to be only factor that influences banana ripening if the ethylene concentration is over 500ppm.
3) Ventilation was considered as an important factor, since it affects gaseous conditions such as O₂ and CO₂ concentrations in a ripening room.
However, CO₂ and O₂ within the range of concentrations used in the experiments did not make any significant differences for banana ripening.
4) The relationships between sugar content of banana pulp and caloration of banana skin, hardness of pulp and CO₂ evolution rate were obtained and shown in Figs. 2 through 4.

View full abstract

The numerical analysis using a weighted average approximation method was examined to obtain solutions of time depedent periodic heat conduction in a semi-infinite solid with adequate accuracy. The results of this study are as follows:
1. A model composed of real and imaginary material was proposed and an approximate condition that numerical solutions can be derived only with one boundary condition at the surface, X=0, was clarified. In this, another boundary condition was unnecessary. Fig. 4 shows the required depth of the model in relation to its Fourier Number.
2. A linear relation was observed between the weight θ and the error of numerical solutions, and the equation (13) was obtained by making use of this results. This equation expressed the optimum value of θ, named the minimum error weight and symbolized by θ₀ in the paper, in terms of R, where R=ΔT/(ΔX)². By use of θ₀, numerical solutions which contained at most 2-3% of error can be obtained.
3. Numerical values were in good agreement with those measured temperatures which were obtained when the surface temperature of material varied periodically but not sinusoidally.

View full abstract

Thermal conductivities and permeabilities for the dried layer of beef samples were determined by applying data obtained during freeze-drying to a model based on the rates of heat and mass transfer in the sample. The drying data and physical properties needed for the proposed model were obtained either from the literature or from the experiments using a radiant heating upon the sample surfaces.The relationships between these transport properties and temperatures as well as water-vapor pressures of the dried layer were determined and the temperature and pressure dependances of transport properties were discussed with reference to practical freeze-drying operations.
The results obtained were as follows;
(1) Thermal conductivity had a tendency to decrease as the dried layer temperature increased as shown in Fig. 7 and there was no definite effect of water-vapor pressure in the dried layer on thermal conductivity in its pressure range from 0.29 to 0.66 torr under conditions of the total pressure in the chamber ranging from 0.3-1.5 torr as shown in Fig. 9.
(2) The regression equation determined for predicting thermal conductivity as a function of the dried layer temperature in the range of 3 to 41°C, was presented by;
k_e=-4.189×10^-7θ+1.511×10^-4
(3) In the model thermal conductivities were calculated by assuming the latent heat of sublimation to be equal to the value for frozen beef juice. The results obtained were about 7% higher than the values using the heat of sublimation of pure ice and about 12% lower than those using bovine muscle.
(4) Effect of error involved in neglecting the heat absorbed by water vapor flowing through the dried layer on thermal conductivity increased in proportion to the dried layer temperature; namely, increasing the temperature from 3 to 45°C leaded to a increase in error ranging from 3 to 7% as shown in Fig. 8.
(5) Permeability K and K* were calculated from both equilibrium water-vapor pressure of pure ice and frozen beef, respectively. The difference between the two values, ΔK was 15-43% as presented in Table 3.
(6) Permeabilities vs. the dried layer pressures of water-vapor relationships were shown in Fig. 10. The values for K were in good agreement with Mellor and Lovett's theoretical curve based on the collision theory developed by Pollard and Present and also with their experimental results using completely freeze-dried samples under steady-state conditions. On the other hand, the discrepancy between K* and their theoretical curve was apparent, as could be seen from Fig. 10.
(7) The relation between permeability and the dried layer temperature was obtained as shown in Fig. 11. As the dried layer temperature was increased, permeability had a tendency to increase at the surface temperature ranging from 30 to 80°C and to decrease from 80 to 100°C. This decrease was attributed to temperature rise at the sublimation front as shown in Table 2. It was considered that in this surface temperature range the heat supplied across the dried layer was dissipated as both sensible heat to raise the temperature of the frozen layer and latent heat of sublimation. Thus the model applied over this temperature range was found to provide invalid values because the drying conditions did not satisfy the assumption used in the model, as expressed by equation (2).
(8) Agreement between calculated values by the regression equation (21) and from Mellor and Lovett's theoretical equation (17) for permeability was generally good at the dried layer temperature up to 20°C as indicated in Table 5, and it was suggested that the effect of the dried layer temperature on permeability was greater than that assessed by equation (17).

View full abstract

Measuring methods capable instantaneously the rheological characteristics of cooked cocoons were investigated, and as a reslt measuring equipments of the stae of cooked cocoons developed.
Some experimental results obtained were summarized as follows;
1. In a simulation, a pulse function was inputted in the 4-element model to measure the behavior of the model.
As a result, the simulation was found to be in an excellent agreement with the waveforms of actual cooked cocoons. It was therefore confirmed that the state of cooked cocoons could be evaluated by the 4-element model.
The response waveform simulated by inputting a pulse wave to the 4-element model displayed a damping curves, which was represented by the first peak Xh, logarithmic decrement δ, response frequency f and the difference h between the original level and convergence level.
2. A measuring equipment based on the simulation method was composed, which displayed on the oscilloscope and records the response waveform cased by a pulse wave impact to a point on a cocoon shell.
3. With the progress of cooking, . the impulse response waveforms of cocoons showed the tendency of lower value of Xh, δ and h, and higher value of f.
And it was known that the experimental results showed the same tendency as the simulation result.
4. In the next place, a measuring equipment by the frequency response method was composed, which displayed on the oscilloscope in Lissajous's figures the phase difference formed combinedly by the input sine waves given to a point on the cocoon and the response waves caused at a certain distance away by the input sine waves.
5. Two types of the frequency response m thod for measuring the states of cooked cocoons were examined.
First, the input frequency given to a point on the cocoon was raised step by step to determine the input frequencies which produced respectively the phase differences of π/2, π, 3π/2, 2π rad in Lissajous's figures.
Secondly, the sine waves of constant input frequency was given to a point on the cocoon, and the states of cooked cocoons were examined by the phase difference.
6. The results obtained by the frequency response method were in agreement with the simulation results of the 4-element model.
According to the frequency response method, it was known that the results showed synthetically the rheological characteristics of cooked cocoons.
7. Thus, the impulse response method and freguency response method were examined to measure the state of cooked cocoons. Particularly, the impulse response method was considerd to be more effective than frequency response method on utilizing the results obtained in the second report (rheological properties of cooked cocoons).

View full abstract

A couple of artificial rough tracks were theoretically designed, which are to be made use of in researches on the improvement of the tractor ride. The profile of the tracks was so determined, that the roughness in general is middle poor according to the road classification criteria of BSI, and that the power spectral density of the surface undulation is expressed with a simple formula. The autoregression method was applied in the stage of the computer generation of the profile data.
Test runs of a tractor on the artificial tracks showed that the tracks as an input device of vibration to tractor secure high consistency, and that the power spectral density of the vibration acceleration at the seat attaching point of tractor on the tracks shows a similar tendency to that obtained in seat test runs on a gravel road. After the appropriateness of the application of the tracks in vibration tests was verified, a certain number of tractors and seats were offered to ride tests. So-called suspension seats were positively evaluated, but also noticed was the significance of the appropriate adjustment of the spring in accordance with the body weight of drivers.

View full abstract