The purpose of this paper is to discuss synthetically on the following items for the both of the experimental and theoretical investigations of the two engines-the eccentric type and the general purpose engines-so far (see the 1st, 2nd and 3rd reports).
(A) Performances (indicated and brake mean effective pressure)
(B) Specific fuel consumption.
(C) Emission gases
(D) Efficiencies
(E) Frictinn losses
The conclusions obtained from them were as follows;
(1) For the eccentric type it was able to change the time areas of the inlet, scavenging and exhaust ports depending on its eccentric rate (ε) and its setting angle (a_A) of a crank-pin position.
By the suitable combination of ε and a_A, the delivery ratios, trapping efficiencies, relative charges, scavenging efficiencies, charging efficiencies, indicated and brake mean effective pressures increased and the quantity of HC and CO in the exhaust gases, and the specific fuel consumptions decreased. Further the NO_x quantities also increased a little with a incease of performance.
For example ε=0.108 and a_A=150deg. at 4000rpm, the indicated and brake mean effective pressure of the eccentric type engine were approximately 20 percent and 13 percent better than those of the general purpose type.
(2) Comparing the eccentric type with the general purpose type when the engine speed is high, the friction loss of gear surface was extremely increased. The losses of the others were however approximately the same (for example, the pumping work in the crankcase), or gave no influence on the performances.
(3) For the industrial and agricultural use (at 2000-4000rpm), the high powers, tow fuel consumptions and low emission gases are desired to be required, therefore the eccentric two strokecycle engine seems to be more useful.

View full abstract

This paper reports how the pressure produced at the injection nozzle by flowing air or N₂ gas is actually varied according to the size of nozzle port, the degree of soil hardness, and the thickness of soil bed layer. The important results from this experiment were as follows:
1. In a sandy soil with less moisture in which the cohesive force between the soil grains was weak, a spouting phenomenon rising up to the surface taked place. (Phot. 1-a)
2. However, in a moist sandy soil or a clayey loam, the above mentioned spouting was not observed, but around the nozzle port some hollows were found and soil around the nozzle port was shifted. (Photo. 1-b & c)
3. In such a high-moist clayey soil as more than 30% in moisture ratio, horizontal large cracks was made around the nozzle port with a little stream of gas. (Photo. 1-d)
4. The produced pressure at the injection nozzle generally shows such a change as a cubic function vs. the flow rate after plotting on logarithmic graph and it takes a maximum value of produced pressure at a certain amount of flow rate at which some shift of soil around the nozzle port is observed. (Fig. 4)
5. Depending on the continuous variation of the flow rate, the produced pressure seemed to be weakned showing hystericis. In this consequence, if we flow the fluid of small quantity after the flow of large quantity of fluid at one time, we can spread the fluid into soil bed layer with small produced pressure and small energy. (Fig. 5)
6. The harder the solidity of soil became, the stronger the produced pressure grew, because the porosity in its soil became smaller and the larger the flow rate at which the produced pressure showed the maximum value, became. (Fig. 6)
7. The produced pressure was bigger when the layer of soil-bed became thicker, which meaned the distance between the nozzle and the surface of soil. Its rate of increase of the produced pressure was however comparatively small. In spite of the increase of the thickness of the soil bed from 19cm to 39cm, the produced pressure increased only to 1 and half more. (Fig. 8)
8. The produced pressure was almost the same in the change of the nozzle in all directions. Any breakdown of soil had no influence on the change of the direction of injection. Moreover, it is concluded that the breakdown or the movement of the soil just under the surface is not due to a kinetic energy of fluid, but a static energy of pressure. (Fig. 9)
9. The larger the injection nozzle port became, the weaker the produced pressure grew. The produced pressure did not become weaker in proportion to the size eventhough the nozzle port was extremely large. (Fig. 10)

View full abstract

Constitutive equation, stress relaxation equation and creep equation were developed under two-dimensional stress state for 3 element Voigt model of soil and prepared in order to validate them by Finite Element Method program.
Outline of FEM program, in which the stiffness matrix was solved by means of unit partition method, was described and its usefullness was clarified.
From the comparison of stress relaxation curves between theoretical and computed (by FEM) results it was found that the computed curve was satisfactorily coincident with the theoretical one.

View full abstract

The mechanical behavior of void water in the general capillary system, which was difficult of hydrostatical analysis, is studied from the standpoint of thermodynamics. The following basic equation of thermodynamical equilibrium in the system is derived.
d_iS=-{σ_GL(dA_GL+dA_SG cos α)+mgdz}/T, (i)
where
d_iS: entropy production,
σ_LG: interfacial tension of liquid-gas interface,
A_GL: area of gas-liquid interface,
A_SG: area of solid-gas interface,
α: contact angle,
m: mass of void water,
g: gravitational acceleration,
z: mean height of capillary raise,
T: absolute temperature.
As an application of eq. (i), the mean height of capillary raise or capillary constant for the spherical particle layer and the irregular particle layer are analyzed under the condition of reversibility, and the following equations are obtained:
For the spherical particle layer
z=6(1-e)σ_GL cos α/eρgd_p (ii)
or
K=6(1-e)/e (iii)
For the irregular particle layer
z=(1-e)σ_GL cos α/e(1/νρ_p)ρg (iv)
or
K=1-e/e
where
z: mean height of capillary raise,
e: void ratio,
ρ: density of void water,
d_p: diameter of particle,
ν: specific area,
ρ_p: density of particle,
and capillary constants for the spherical and the irregular particle layer are denoted by K_s and K_i respectively, i. e.,
K_s≡ρgd_pz/σ_GL cos α
K_i≡ρgz(1/νρ_p)/σ_GL cos α
It was shown further that eqs. (ii), (iii), (iv) and (v) provide either the upper or the lower limit for the actual irreversible process according as a direction of the movement of void water.
The eqs. (iii) and (v) are compared with the experimental values. As shown in Figs. 4 and 5 the validity of the present analysis are demonstrated.

View full abstract

It was observed from the tests of single wheel apparatus in door, that the theoretical equation on side force derived by E. Fiala agreed well with the experimental results. According to this equation, the side force of wheel under skid was estimated by the followings: the frictional resistance at the contact surface of wheel, rolling resistance, drawbar load, side slip angle and a factor of cornering coefficient.
A factor of cornering coefficient (C), which could not be measured directly, was one important parameter in appraisal of skid the empirical equation of C on farm was obtained from the experimental results of single wheel.
In this paper, the applicability of the empirical equation was discussed on the basis of experimental results in hilly land, using the two wheel tractor with agricultural tire, double tire and steellugged wheel (attached with the non-skid plates), respectively.
Main results were as follows:
(1) On the rolling wheel of agricultural tire and double tire, the estimated valus of C calculated from the empirical equation agreed well with the experimental values at 10 degree of the inclination angle of land, but not at 20 degree because of the slippage among soils.
On the steel-lugged wheel, the experimental values were larger than the estimated values due to the effect of non-skid plates.
(2) On the driving wheel of agricultural tire and double tire, the estimated values of C agreed well with the experimental values under the small drawbar load. It did not agree however under the large drawber load, and the side slip angle became large due to the slippage among soils.
(3) At the large inclination angle of land, steellugged wheel was better than the others because of the increase of the frictional resistance to the contact surface, preventing the tractor from skid.
(4) From these results, the empirical equation of C agreed well with the experimental results for the skid except the effect of slippage among soils.

View full abstract

To develop the automatic sacking device for JIDATSU combine harvester (Japanese type combine harvester), three prototypes, AP 743, AP 744 and AP 755 were designed and tested in the laboratory and the field from 1974 to 1975.
AP 743 consists of the tank with two chambers, shatter, shoot, cam type bag divider, a revolution clutches and grain height sensors. Basic structure and sacking method of this machine was similar to AP 732.
As the results of the laboratory test of this machine, the sacking errors were observed frequently because of the difficulty in keeping the relative position between cam of the divider and the hook of bag constant.
AP 744 and AP 755 were modified on the basis of the data obtained from AP 721, AP 732 and AP 743. And these machines were attached to 4 row JIDATSU combine harvester.
The model AP 744 mainly consists of auger type bag divider, grain tank with rotary discharger, level switch, shoot and bag vibrator. And these units well driven by direct current motor. The basic structures of AP 755 were similar to that of AP 744, except a little modification in the shape of shoot attached with shoot error sensor, warning buzzer and lamps.
From the field test of harvesting rice and wheat all the units and mechanisms of these machinery were satisfactorily operated.
The details of the shape of grain bags and the mechanism of units will be reported in Part 3 and Part 4.

View full abstract

(1) The characteristics of indicial and frequency response of the feedback control system with electro-hydraulic servo-mechanism were tested by using the following test signals; step input and sine wave input. And the most suitable operational technique was discussed when employing this system for the automatic position control of cutter bar for tea-plucking machine.
(2) The transfer function of this control system could be approximated as first or second order time-lag element when the transformed output was given as indicial or frequency response.
(3) An increase in the sensitivity of servo-amplifier makes the time response of both indicial and frequency response higher, and the time required for the response to reach the final value is shortened.
(4) As the characteristics of the frequency response, the gain (the ratio of input to output) decreases and the phase-lag increases as the input frequency becomes higher, and the degree of its increase and decrease becomes great in inverse proportion to the sensitivity of servo-amplifier.
(5) When employing this control system for the automatic position control of cutter bar for tea-plucking machine, the desirable characteristics of the frequency response are as follows;
(a) The gain must equal unity or so for the wide frequency range regardless of the sensitivity of servo-amplifier.
(b) The phase-lag must equal the time required for the tea-plucking machine to advance the distance between the sensing plate and the cutter bar. This delayed time was expressed in terms of phase angle as equation (11).

View full abstract

The physical properties of root vegetables were investigated for the development of root vegetable harvester using three kinds of radishes and two kinds of carrots. As indexes for physical properties, the tensile strength of petioles, the bending strength of hypocotyles and the size of hypocotyles were measured. In the results of measurments, the distinct differences between the radishes and the carrots were recognized for the indexes of the physical properties. The tensile strength of petiole of radishes was distinctly smaller than the carrots. But the size of hypocotyle of radishes was distinctly larger than the carrots. It suggested that mechanisms for harvester which pulled them up on petiole were not suitable for the radishes and those which pulled them up on hypocotyle were not suitable for carrots. Those facts suggested the necessity of development of the new harvester which had some mechanics for pulling up root vegetables without holding them directly —for example, pulling up root vegetables with the around soil—.

View full abstract

The drying characteristics curves of a single paddy grain including a large drying rate of early drying period were represented by two drying period of Fig. 1 namely period I (a-b) and period II (b-o).
In this paper the forced air drying theory was combined with the above drying characteristics and the new drying equations were presented.
The results obtained were as follows.
1) The drying contant and equilibrium moisture content for period I were give in Eqs. (24) and (27) where K_I′ was the modified drying constant for period I.
2) The second critical moisture content M_k between period I and II was given in Eqs. (26), (28) and Fig. 4.
3) The drying process of bulk was divided in period I, mixed period and period II as in Fig. 2.
The Eqs. (10)-(13) were for determination of moisture content and drying rate of bulk for period I.
The mixed period was the period between τ₁′ (eq. (14) and τ₂ (eq. (16)).
Bed depth ζ_k of zone II was obtained from Eq. (17) and the bed depth of zone I was ζ_L-ζ_k.
The moisture content and drying rate of bulk for mixed period were calculated by Eqs. (20) and (21).
The moisture content and drying rate of bulk for period II were calculated by Eqs. (22) and (23).
The computational results compared with the experimental data are shown in Table 2. Experimental conditions for each test run are slso given in this table. The results are also shown grafically from Fig. 5 through Fig. 8.
4) Fig. 9 is the hypothetical drying characteristics of intermittent drying. Figs. 10 and 11 are the computational and experimetal results for intermittent dryings.
The equations in this report better explained the results of intermittent drying and the results of drying using large air volume than the equations in previous report by the same anthers.

View full abstract

From the analysis of the separator of indent cylinder type, the separating factors were clearly defined and their effects were discussed. In addition, the separating mechanisms were modelled, the fractional recovery curve was calculated and compared with the experimental values. The obtained results were as follows:
1) Besides the factor of grain length, the separating factors included the shape and coefficient of friction of grain. The distribution form of the values of physical properties of these factors also had strong effects on the separating performance.
2) The factors which had effects on the separating performance are: size, shape and arrangement density of indent parts; size, number of revolution and material of cylinder; separating time, hopper angle and supplied quantity. It is possible to improve the separating performance if these factors are suitably selected.
3) The boundary value of width of broken and whole grain, and half of this value can be used to determine the width and depth of indent parts respectively.
4) The separating performance was good when the coefficient of friction of grain-cylinder was high, and the improvement of this performance was assured if the grain of which thickness is small was removed by a thickness grader before separating.
5) The separating accuracy was good when the separating time was long, and the hopper angle could be properly selected by regulating this angle in such a way to get the value P_B which should be high and small in terms of broken and whole grain respectively. P_B was the probability of grain entering the hopper being carried by indent parts.
6) The fractional recovery curve was calculated as in Equations (2-6), these results agreed with the experimental values, and were expressed in Figure 9.

View full abstract

This paper described the effect of an internal curtain on temperature distribution and heat flow rate from the roof in a greenhouse covered with plastic film. The greenhouse used was shown in Fig. 1, and the internal curtain material provided was a transparent polyethylene plastic film with 0.05mm in thickness.
On this heating system hot air (approximately 50°C) blew off through the outlets of polyethylene duct to heat up the air in the greenhouse. The air temperature became higher with height from the soil surface.
The air temperature of the upper portion (2.8-4.1m above the soil surface), which appeared not to be related with the plant growth, was usually higher than that of the lower portion (0.2-1.0m above the soil surface), which appeared to be related with the plant growth. It became 2.3-4.1°C higher when the temperature difference (Δt) between the inside and the outside was 9.7-13.1°C. When the internal curtain was installed, the air temperature of the upper portion became lower than that of the lower portion. It became 6.9°C lower when Δt was 15.6°C. It was shown that the internal curtain in the greenhouse reduced the unnecessary air heating.
In regard to the uniformity of air temperature, the maximum values of temperature difference and standard deviation in the case of internal curtain installation were larger than in the case of no internal curtain installation for heating volume in the greenhouse was decreased. But mean temperature distribution became more uniform because the heat insulation was improved resulting in the decreased heater operation.
The internal curtain installation resulted in a lower heat flow rate from the roof by means of the lower air temperature under the roof. The values of heat flow rate were equivalent to 55-60% in the case of no internal curtain installation. In addition fuel consumption was equivalent to 36% (Δt=10°C) and 50% (Δt=15°C) in the case of no internal curtain installation.

View full abstract

The noise from Farm machinery was recorded and played back as the noise source. This noise data was used in the noise absorption test for trees and shrubs.
The following matters were clarified.
1) The capacity of noise absorption due to trees and shrubs was concerned with the area of its leaf surface and with the density of its leaves. This needs higher value and that needs greater size at lower frequency ranges (63-250Hz). At higher frequencies (4-8KHz), even the smaller leaves can produce enough absorption effect. But, at medium frequencies (500Hz-2kHz), there aren't any trees or shrubs which can decrease noise level sufficiently.
2) It seems that noise propagation reaches the peak of sound pressure level at the distance of integer times of the wave length. And more effective abatement can be attained by means of trees and shrubs which can absorb the reflection and the diffraction noise at the above distance.
Although the loud-speaker used in this study is far different from the farm machinery with regard to the sound radiation and the sound power, it can be used as the noise source to study the characteristics of noise absorption due to trees and shrubs, not only to study absolute quantity of noise absorption.

View full abstract

Psychometric studies on grading work of vegetables and fruits were carried out using Kaki (Diospyros Kaki L. cultivar. Fuyu). Since the actual farm products were usually perishable and changeable the color slide pictures of Kaki in place of the actual ones were investigated here.
Analysis of percentages of three grades judged, the rank of grading and the factors affecting judgment revealed that although there are less informations on chink between calyx and flesh, hardness and shape of fruits than those of actual fruits, their color slide pictures could be successfully used for the purpose of the present study.

View full abstract