This paper deals with the comparison of the theoretical discussions (in Ist Report) to some experimental results on the relations between the blowback and the performance of the small two-stroke cycle engines.
In every experiments above mentioned, we measured the pressures in crankcase, scavenging passage, cylinder, inlet and exhaust pipe, the components of gas, CO₂, O₂, CO, in cylinder, scavenging passage, crankcase and exhaust tank, and investigated the flow in scavenging passage by means of a high-speed photography of the smoke mixed in it.
The conclusions obtained by this investigation and that in Ist Report are mainly as follows.
(1) The best value of charging efficiency is obtained at the appropriate quantity of the blowback.
This charging efficiency in deeply relevant to the performance (mean effective pressure).
(2) The faster becomes the engine speed, the larger becomes the exhaust port height giving the appropriate quantity of the blowback.
Notwithstanding the pipe systems (as inlet, exhaust and scavenging passage) are considered or not, the conditions of (1) and (2) above mentioned are qualitatively realized.
(3) In case of the quantitative judgement of the efficiency, the scavenging passage is regarded not as pipe but as volume.
Futher, in this case, the condition between perfect diffusion and half diffusion is considered better than that of stratification.
It is also considered from the point of view of visibility by means of the high-speed photography.
(4) Even if much quantities of the blowback exist, an abnormal explosion between the blowback (burned) gas and the mixture (gasoline and air) is not produced.
(5) In addition, we also cleared up the influence of inertia-effect and pulsation-effect to delivery ratio.

View full abstract

Small powered tractors were surveyed and tested for power train performance and durability by examining their use, maintenance, breakdowns and replacement. Many tractors were surveyed throughout Japan and some were tested in the laboratory. The results were as follows:
1. The annual hours of use decreased when tractors became 5 years old and maintenance requirements increased after 2 years of use. However, the performed maintenance decreases when a tractors is 2 years old.
2. Fifty percent of the tractors was replaced at about 7 years of age. At 5 years of age used tractors has depreciated by 20 percent.
3. The operated hours of tractots for 10 years was mostly 300 to 500 hours.
4. After 300 to 400 hours of use without maintenance, 10 to 20 percent output of the tractors failed. Good maintenance is important for a longer life.
5. The failure rate of the tractors used by farmers, was equal to the failure rate of bench tested tractors under 2/3 of max. power output without maintenance.

View full abstract

A basic analysis to clarify the stuctural damping of tractor frame has theoretically and experimentally been developed. Several finding can be drawn as follows.
1. In theoretical analsis, the motion equations of a mathematical model are described using second-order linear differential epuation to investigate the sinusoidal response characteristics. It is of great interest to note that the generation of peak values in gain curves are clearly evident due to manipulations of parameters, e. g. η, k₁, k₂, k₃.
2. In case two peak values take place in bode diagram, it can be assumed a peak value in low frequency region might be resulted from wheel systems and the other one in higher frequency region tractor frame itself.
3. It is impossible to neglect the effect of η in terms of strong correlationship between torsional angle ratio and frequency in amplitude dependent characteristics.
4. The possibility of practical application of the paramenter estimaton by means of manipulation of parameters in theoretical equations are partly verified.
5. Experimental results indicate the necessity of considerations directed to the structural damping while are dealing with the resilient vibrations of tractor frame.

View full abstract

Analyzing photographs of a soil deformation by a model track which was forced to slip, following results were found.
1) Soil was sheared by the track in an upper layer.
2) Soil displacement was proportional to a distance from a leading edge and a slippage.
3) Shear pattern was a plane at the depth of grousers in the case of no space track.
4) In the case of spaced tracks, shear patterns were able to hypothesize to consist of such a logarithmic spiral plane and a plane as the cast of a model shoe.

View full abstract

Analyzing a pulling resistance of a model shoe depending on a soil shear stress, a soil shear strength and a soil deformation pattern described in the part I in this report series, following results were found.
1) It was impossible to apply the soil shear stress diagram directly to estimate the pulling resistan-cedisplacement curve, because there was indisputable difference between both coefficients which correspond to displacements at peak values.
2) The maximum pulling resistances of model shoe in cohesionless soil were calculated theoretically from the forces' equilibrium in the shear pattern of frictional soil. And they coincided well with measured values.
3) In the case of cohesional soil, the maximum pulling resistances were calculated theoretically, assuming that the shear pattern of logarithmic spiral type would occure under each cleat. They also coincided well with measured values.
Consequently, it would be said that the validity of the assumption of shear pattern was apparent.

View full abstract

propulsion of a model track was calculated theoretically, depending on a shear pattern, a soil shear stress diagram and a contact pressure distribution along the track which ran at a certain slippage on a sandy loam in a soil bin. Findings from this study are as follows:
1) Shear stress τ was represented as a function of pressure p and displacement d, ie.
τ_d=c_d+p·tanφ_d
And c_d and φ_d were also functions of displacement d and were obtained by author's proposed equation.
2) Contact pressure revealed a peak under supporting wheels of track and increased at rear area with increasing of slippage.
3) Propulsion distribution of a single cleat was influenced by the pressure distribution.
4) Propulsion variation of the track was pariodic.
5) Displacement modulus Kτ (or Kτ_c and Kτ_φ) should be multiplyed a data by a certain rate when it was applied to calculate the propulsion, comparing a measured pull-slippage curve and a calculated propulsion-slippage curve.
6) Propulsion of spaced track was more than that of no space track by the effect of increasing of contact pressure.

View full abstract

In this report, the torque losses using the calculating equation of power sprayer performance are analyzed, and the mechanical efficiency of power sprayer in a designing process are predicted by these calculating equations.
We were considered with a algorism to obtain the optimum values of plunger diameter and stroke giving a maximum mechanical efficiency in power sprayer.
Its algorism was programed by FORTRAN, and the designed calculations giving a discharge flow and a rotational speed of power sprayer were done by digital computer TOSBAC-3400/41.
The following results obtained.
(1) The torque loss was occured by the friction, in part of plunger seal, was fairly large value.
(2) The optimum values of plunger diameter and stroke calculated by this program were agreed with the these values in power sprayer supplied the previous experiment.
(3) If these were of the same contact width in part of plunger seal, a combination value of plunger diameter and stroke having the smaller stroke was shown the smaller torque loss.

View full abstract

Parboiling process consists of soaking, steaming and drying. The properties of parboiled rice may be formed by many kinds of processing conditions which are concerned with one another.
This investigation was carried out to determine a practical and rationalized method for producing parboiled rice, considering these processing conditions.
This paper is based upon laboratory tests conducted to find out the rate of gelatinization of parboiled rice starch.
The results obtained are as follows.
(1) The rate of gelatinization of parboiled rice starch increased with increase of water absorbed during soaking.
(2) Under special soaking condition with some various steaming conditions, the rate of gelatinization increased with rising of steaming temperature and prolonging of steaming time. From these results it was recognized that gelatinization was considered as an endothermal reaction and the rate of gelatinization depended upon amount of heat supplied by steaming.
(3) The rate of gelatinization on products was profoundly influenced by not only moisture in soaking and heat quantity in steaming, but also drying conditions.
(4) As the rate of gelatinization is intimately related to over-all conditions of soaking, steaming and drying, it may be considered as a good indication to determine the effectiveness of parboiling treatment.
(5) The dimensions of parboiled kernels which were thoroughly subjected to moisture-heat treatment decreased by contraction with comparing to untreated kernels.
(6) The parboiling system in Fig. 8 will be considered as feasible system for both dried paddy and raw paddy because it is designed so as to be also available and raw paddy for high moisture paddy newly harvested.

View full abstract

For the purpose of inquiring into the shaking frequency that caused the citrus fruits to detach efficiently from the tree, the frequency response of it's fruit-stem system to forced vibration was, observed and simultaneously, the various forces applied to the stem ware measured, The mechanical models of the fruit-stem system were chosen for the numerical analyses of it's motions and the predicted motion was compared with the observed motion.
1) Motion picture analyses of the vibration characteristics of the fruit-stem system were made for Citrus Unshiu. The results of them are shown in Fig. 8 or Tab. 1.
2) The numerical analyses of the two mechanical models, double physical pendulum model and curved beam model, could make clear the vibration charcteristics of observed motions of Citrus Unshiu. Therefore, the motion characteristics of the fruits that bear in an orchard may be predicted from the investigation of their bearing conditions.
3) As the natural frequency of the first fundamental mode of double physical pendulum was under 2.5Hz, the inertial force due to the resonant motion of the fruit was too weak to detach the fruit from the tree. This mode, that induces the simple pendulum motion, should not be used to detach the fruit because the fruit damage of predetachment may be produced.
4) Twisting mode existed at the range of 5 to 7Hz and the torsinal moment due to the resonance was under 0.2kg-cm. If fruits are detached by only a tortional operation, the torsional moment of average 1.1kg-cm is required to shear the stem of Citrus Unshiu. Therefore, this mode cannot be used to detach the fruit.
5) When the second fundamental mode of double physical pendulum was induced, the ralative bending angle between the stem and fruit was maximized into approximately 70-80° and tensile and compressive force of the stem became larger, too. These natural frequencies were 6-8Hz in y-z coordinates and 8-10Hz in x-z coordinates. This mode is considered to be most suitable to detach the Citrus Unshiu's fruits from their sepals.
6) The second mode of trasverse vibration of the stem occurred at 14-15Hz in response to exciting displacement to have vertical component and the tensile and compressive force was increased rapidly at this time. If all the fruits, that bore in the orchard, could be shaken by the oscillating displecement to have vertical component, this mode would be used to detach the fruits. However, the more delaied experimental studies and field tests must be made, because the range of natural frequencies to induce this mode may be extended by the difference of physical property of each stem and the mature Citrus Unshiu's rinds are so tender and apt to float that a portion of their peels may be torn with the stem during detachment.

View full abstract

It was very difficult to assume the quantity of Chlorophyll by Hunter renotation system, therefore the quantity of Chlorophyll was measured by concept of the color difference.
The results were as follows:
1. There were high correlation between the quantity of Chlorphyll (C) and the color difference (ΔE).
2. The correlation between the quantity of Chlorophyll and the color difference was influenced by determination of standard value for the color difference.
3. In order to correct the above defect, a model leaf was assumed. Satisfactory results were obtained by deduction with graphs which regardd a model leaf as standard value.

View full abstract

Tests were conducted to find the effects of moisture content, cutting length and date of cutting on the resistance to air-flow through orchard grass hay.
Hay samples were packed into the bin of 7.7cm in diameter to a depth of 30cm.
Pressure drop-air flow relationship was observed for various hay density (D. M 50-250kg/m³), moisture contents (wet basis 20-80%), cutting length (2-3cm, 10-20cm, no cutting) and date of cuttting (first and second).
The results were as follows:
1) The general equation for air flow through hay in a depth of 30cm is
P=KD^mVⁿ(=kd^mVⁿ)
Where p: Pressure drop, mmAq
K, k: constant for material and test condition.
D: dry matter density, kg/m³
d: apparent density, kg/m³
V: air velocity, m/s
m: density exponent.
n: velocity exponent.
2) Coefficients K, k, density exponent m and velocity exponent n were not affected very much cutting length.
3) Velocity exponent n reduced slightly as dry matter hay density increased, moisture content increased and second cutting hay was greater than first cutting hay.
The value of first cutting hay was 0.9-1.3, second cutting hay was 1.1-1.3
4) Coefficients K, k reduced as moisture content increased. Density exponent m increased slightly as moisture content increased. k, m of first and second cutting hay was respectively as follows:
m₁=0.02512M+2.0197
Log k₁=-0.07048M-1.9391
m₂=0.02512M+2.5108
Log k₂=-0.06118M-2.9636
5) Resistance to air flow decreased as moisture content decreased with the same dry matter density.
6) First cutting hay had a lower resistance to air flow than second cutting hay with the same dry matter density.

View full abstract