The emulsified fuel will be one means to reduce some harmfulness to the human body and to plants in using farm diesel engines both indoors and out-of-doors. This paper discussed about the various engine performances under heavy loads and efficiencies associated with injection timing and cetane number improvers.
The experimental results may be summarize as follows.
1. Rated (Cruising) horsepower of diesel engine is decided by black smoke concentration, therefore rated (cruising) horsepower in the case of using emulsified fuel is larger than diesel fuel by attaching a plunger pump with larger inside diameter.
2. As injection timings were delayed, NOx emission as well as black smoke decreased with the decrease of the temperature of main combustion chamber. The reason for the decrease of NOx by using emulsified fuel was mainly due to the reduced time of high temperature in the combustion chamber.
3. When the W/F ratio in emulsified fuel was above 0.5 and partial load was above 7/8, CO concentration became larger than diesel fuel, and especially CO concentration in the case of W/F=1.0 became three to ten times as much as diesel fuel.

View full abstract

Several papers have been published on the subjects of steerability and trailer towing performance of the wheeled tractor. However, there has not been any article dealing with the same subject of the tracked tractor, because the phenomenon of those dynamic motions between tracks and ground is very complicated.
This paper describes a theoretical analysis of uniform turning motion of tracked tractor with wheeled trailer. Considering all possible factors related to steering problems such as track slippage, towing load and length of towing bar, equations for uniform turning motion have been developed in order to analyze and predict steering dynamics and steerability in the plane motion of the vehicles. These equations have been numerically solved by a digital computer and the reliability of the above analysis has been confirmed experimentally by using the scale models.
The results are summarized as follows;
(1) The equations of turning motion presented here provided a reasonable means for a dynamic analysis of the tracked towing vehicles.
(2) The turning radii are closely connected with towing weight and track slippages, and they increase rapidly when the towing weight increases.
(3) The turning radii of tractor and trailer are not related to the length L₂ of towing bar at L₂<L (track contact length), however, at L₂>L radii are affected considerably.
(4) The steering characteristics of tracked towing vehicles tend to oversteer at higher speeds as shown in Fig. 10.

View full abstract

It is a difficult problem to analyze the soil thrust of tractors or the resistance to tillage implements because it includes the failure of soil. The analysis of deformable body is usually made with continuum model. Continuum model is naturally important, but it is not necessarily suitable for the problem of deformable body with failure, because its fundamental concepts of stress or strain tensors lose their meaning where failure arises. This study tries to develop a method of analysis on deformable body by using a discontinuum model founded on the concepts which are quite different from those of continuum model. This method will generally be able to deal with small deformation to large one with failure, because the fundamental concepts of discontinuum model are independent of the deformation of the model system.

View full abstract

Recent popularization of rotary tillage in Japan is quite remarkable along with riding tractors. Insufficient knowledge on the characteristics of power transmission of a rotary tilling tractor may causes inappropriate tractor design, test method and so on. The authors studied the power transmission characteristics including external forces acting on a rear-wheel drive and a four-wheel drive tractor in rotary tillage. The results obtained are as follows:
1) The power transmission system of a rotary tilling tractor forms a closed-loop.
2) The rotary axle power achieves tillage work in which reaction forces from soil act to the machine. The reaction forces as the external forces on the tractor act as the tractor-travel-power calculated by the equation (40-3) and feedback-power calculated by the equation (70) through drive-wheels into the closed-loop transmission system of the tractor.
3) The sum of both tractor-travel-power and feedback-power is named return-power of the rotary tilling tractor. The ratio η_r of the return-power to the rotary axle power is several percent according to the example calculated by the equation (40-2). (6% in example)
4) The ratio of the rotary axle power L₃ to the engine output power L_E in the closed-loop system is L₃/L_E and denoted by η_R for the rear-wheel drive tractor and η_A for the four-wheel drive tractor, and calculated by the equation (42) and (65) respectively. Here η_R and η_A are named “overall power transmission efficiency of the closed-loop system” of the rotary tilling tractor.
5) There is negligible difference between the overall power transmission efficiency η_R of the rear-wheel drive tractor and η_A of the four wheel drive tractor. The velocity difference between the rear and front wheels also gives negligible influence to the overall power transmission efficiency.
6) These efficiencies η_R and η_A are several percent larger than the efficiency η′ in the open-loop system without any feedback from the return-power of the rotary axle power. This percentage will be about a half of the ratio it η_r of the return-power in general.
7) Among many factors in the equation (42) and (65), the efficiencies of each power transmission element η₁, η₂ and so forth, rotary tiller weight W_R, tractor weight W_T are more sensitive than other factors to the changing value of η_R and η_A. Thus, increasing n1, n2 and so forth and decreasing W_R and W_T in the range of tractor motion stability are important design factors to get better overall power transmission efficiency.
8) It is necessary to realize the field condition of rotary tillage which forms a closed-loop power transmission system to conduct the tractor bench test such as durability test. One method for this purpose is to give several percent larger engine power than the original engine power to the transmission input shaft of the tractor. The other is to give additional drive power calculated by the equation (70) to the wheel drive axles by another power source.

View full abstract

A balanced oscillating method was used to reduce the draft force of male drainer as well as to lighten severe vibration caused by single oscillating method. With the results of the model tests, a prototype machine was designed and built to be able to oscillate two moles horizontally with same and different amplitudes, or inclined oscillation of the rear mole. The performance of the machine was tested in the field. The results are as follows:
1. The acceleration of vibration on the balanced type machine was decreased by 34.5 to 42.8% compared to that of single mole type. The amplitudes of variation in the moments of the rear shank were decreased with the increase of velocity, and the acceleration of vibration was decreased.
2. The draft force of the balanced type machine was decreased by 27.2 to 58.8% compared to that of non-oscillating machine, but increased 7 to 40% in comparison with that of the sigle oscillating one.
3. The oscillating torque was increased as the mole's amplitudes and frequencies increased, and the oscillating power became sometimes more than the draft power. The total power requirement was increased with the increase of frequency and velocity. It was observed that the total power requirement became less than that of non-oscillating operation at certain velocities and frequencies.

View full abstract

This study is on a newly developed device of the seed pipe in the direct sowing machine in the underground sowing of rice seeds in the submerged paddy field.
The main points in structure (Fig. 3) are as follows. Seed pipe comes down vertically from the seed metering device and intersects the horizontal seed pipe. A blower is at one end of the seed pipe and a throttle valve is set to the blower a little way from the intersection. Air blast is utilized through the seed pipe to transport the seeds and set them into the soil under the standing water in the paddy field. It is effective in preventing the clogging in the pipe.
1. Though the seed hopper and the seed metering device are not completely closed, the throttle valve prevents the counter blow of the seeds back into the seed pipe. It makes a low pressure space in the seed pipe which results in smooth passing of seeds down into the seed pipe.
2. The velocity of seeds through the seed pipe varies with that of the blast, the adjustment by throttle valve and the dropping patterns of the seeds to the seed pipe.
3. As the ratio of the seeds in the air blast is small, the seeds are transported uniformly through the pipe if the velocity of the air blast is more than 18m/sec.
4. In order to set the seeds in the soil under the standing water, the seeds need to be spouted out with the velocity more than 10m/sec.
5. According to the test results of the trial machine, the velocity of the air at the spout needs to be more than 17m/sec to prevent clogging in the pipe, but it must be less than 25m/sec to prevent the scattering of the seeds and the disturbing soil surface by the blast.

View full abstract

1) A pipeline method was considered to automate the pest control systems in the sloping orchard and to make the spraying pressure of each sprinkler uniform. To grasp the operation of the system, fundamental experiments were done. When liquid pressure at the pilot valve was maintained within the set pressure range by increasing pump pressure, the water pressure valve installed at the sprinkler lateral was opened by the hydraulic signal from the pilot valve. It was confirmed that this method had a possibility for uniform spraying, but at the flow changing time the pump pressure decreased considerably, and so improvement of the pressure control valve might be necessary.
2. This pipeline method applied to a sloping orchard was simulated by a digital computer and the suitable pipe diameters and lengths were obtained for each of the set pressure. In case that such pipes were chosen, the k, S values of the pilot valve were calculated.
3) The spraying pressures of the sprinklers installed at the laterals should be as uniform as possible at the minimum pipe cost.
Five pipeline types were considered and the spraying pressures of ten sprinklers, their mean and standard deviation of each type were calculated. However, in this calculation model these net work pipeline methods were not so economical in comparison to the usual method.

View full abstract

Using a conduction calorimeter, the authors measured enthalpy changes of foods and gelatin models in the temperature range from -40° to 20°C.
The effect of water and solute contents on enthalpy of foods was conspicuous from the measurements of enthalpy.
The following relations between enthalpy (H, kJ·kg^-1) and water contents (w, weight fraction) were obtained from the data of model foods to propose a method of estimating enthalpy of foods.
H(293)=442w+45
H(mp)=428w-21
H(253)=39
H(243)=18
When these equations were used to estimate enthalpy of 30 foods whose experimental data were already reported, it was confirmed that the method was simple and accurate regardless of kinds of foods. The method can be applied to the foods whose water contents are more than 40% and fat contents are less than 10%.
The effect of melting of fats was conspicuous in various heats which were related to the estimated enthalpy.

View full abstract

The scorching characteristics of beef surface during a freeze drying process were obtained correlating with the surface temperature and drying time. Color change of the beef sample surface was measured by comparing visually with standard color chart and expressed according to the Munsell renotation system specification.
The results obtained from these experiments are summarized as follows.
1. At surface temperature range between 45-130°C, the observed change in Muncell hue, value and chroma of the beef surface was as shown in Fig. 2-(a), (b) and (c), respectively.
2. A stage at equilibrium where no further change in surface color detected was found after the drying time had elapsed for about 30 hours. The relation between the equilibrium color (E. C.) of dry beef surface and the surface temperature was shown in Fig. 4. Regression lines in Fig. 4 were formulated in the forms indicated by equations (4-1) to (4-3).
3. The E. C. was related to surface temperature and surface color data of the raw beef in the form indicated by equation (8). This equation might be useful in estimating the degree of scorch and to set a corresponding condition of drying temperature.

View full abstract

The vibrational resonant frequency of watermelon was investigated in order to evaluate the internal quality nondestructively. The results obtained are supposed to be applicable for the determination of the maturity date for picking in the field and for the automatic mechanization of grading for watermelon in the packing line.
1. Sugar content, specific gravity and compressive strength of flesh had a high correlation with the accumulated temperature of watemelon in the field, and proved to be useful factors for the quality determination.
2. The resonant frequency of sound watermelon was not changed by the direction of vibration in both type A and B (Fig. 1). Therefore, the internal quality was evaluated by the one-direction vibration.
3. The resonant frequency appeared in the lower frequency ranging from 150Hz to 450Hz, and the change of resonance pattern was not affected by the type of vibration (type A and B).
4. The amplitude of resonance for watermelon with cavity decreased remarkably as compared with that of sound one. The decreasing amount of the amplitude was proportional to the volume of cavity in the watermelon. The pattern of resonance changed with the direction of vibration applied to the watermelon.
5. The resonant frequency of watermelon transferred to the lower side due to the increase of the weight. Supposing the watermelon as 2-media elastic sphere model, the relation among resonant frequency (f), weight (m) and shear modulus of flesh (μ₁) was obtained as follows;
f²·m^2/3_??_μ₁
This indicated that f²·m^2/3 was not affected by the weight of watermelon, and agreed with experimental results.
6. The index of f²·m^2/3 had a high correlation with compressive strength of flesh, a correlation with specific gravity, but no correlation with sugar content of the flesh.

View full abstract

For the purpose of practising a resonable and effective simulated transportation test in the laboratory, vibrating characteristics and in-transit mechanical injury of lettuce filled in carton-boxes and stacked in seven layers were examined. The results were obtained as follows.
1. Transmissibility of acceleration and phase characteristics of the stacked carton-boxes.
(1) Transmissibility of acceleration of carton-boxes was affected by the banding and the location in the stack of carton-boxes.
(2) The maximum transmissibility was obtained at the top carton-box of the seven layers at the frequency of 8Hz for the unbanded and 13Hz for the banded stack of the carton-boxes. The frequency was considered to be resonant.
(3) The effect of banding on decreasing the acceleration in the carton-box was expected at the frequency lower than 10Hz.
(4) Phase difference between oscillating table and carton-boxes changed much due to the frequency, location in the stack and banding practice. The phase difference was minimized by banding at the frequency lower than 10Hz.
2. Transmissibility of acceleration and phase characteristics of lettuce filled in the carton-boxes.
(1) Resonant frequency of lettuce filled in the carton-box was in the vicinity of 28Hz.
(2) High acceleration which occured at the upper part of the stack was prevented by banding at the frequency lower than 10Hz.
(3) Phase difference between lettuce and carton-box was small at the frequency less than 10Hz, then increased with the increase of frequency although it was not affected by banding.
3. Factors affecting the damage of lettuce in the carton-box.
(1) Damage of lettuce, under the multi-stacked cartons, should be considered only at the frequency of about 10Hz.
(2) Lettuce was damaged by a free rotating motion in the-carton-box excited by the resonant frequency.
(3) The relation between G and N was obtained as follows.
G^4·17·N=5.32×10³
G: acceleration of lettuce in carton-box.
N: repeating number of vibration permissible from the point of marketability.
(4) Damage was reduced by filling the lettuce in the carton-box with cutting butt downward.

View full abstract