A pitch control system for a rotary tiller attached to hydraulic power tractor was investigated in field tests. (1) The hydraulic power system drives both hydraulic motors for tillage and for travel in a hydraulic series circuit. (2) As tillage torque varies in proportion to tillage pitch in constant rotary speed, it is possible to do a pitch control of torque by changing the travel speed. (3) As torque for tillage increases, torque for travelling decreases, because the tractor is pushed by forward component of resistant force of tillage. (4) As tillage torque is changed with this pitch control system, travel speed of the tractor, therefore tillage pitch, is controlled. (5) Travel speed of the tractor follows total pressure P1 and disturbance torque of rotary tiller is controlled. (6) In result of tests, torque of tillage was not always controlled satisfactorily, because the value of gain constant is not suitable for the system and the offset is large. It is, therefore, possible to obtain the better controlling effects by selecting suitablly the system sensitivity and the system elements.
The author proposeu the expressions (1), (4) in the previous papers in order to estimate the soil thrust in paddy fields in our country. From the model test in our laboratory, the author found that the expression (1) could be applied for the estimation of τ-ε curves, from which the soil thrust could be calculated, but there are considerable difference between the experimental values and the calculated values due to the disagreement between the shearing mechanism, the height and shapes of lug and of compressive plate of Burggraf Shear Apparatus. The author would like to make much efforts to obtain more precise soil thrust formula
It is essential to make straight and parallel rice-planting rows to expect a satisfactory subsequent operation such as hoeing and harvesting with rice-binder. But the straight running of the machine in the submerged field is very difficult. Since it is one of the problem how to express the situation of the planting row, the following six specific characters obtained with the statical method are introduced in the present paper. They are related to the straightness of row, the variation of row to straight, the parallelness of row, the directioness of row, the mean distance of row and the mean space of plant. The situation of the planting row was strictly shown by these characters, and it can be supposed that the factors which influenced on these six characters are the steering technique, the field conditions, and the running or supporting device of transplanters. According to the analysis of variance, the straightness of the planting row was much influenced by the factors of steering technique.
It is the purpose of this study to find out whether the rotary pump is applicable to power sprayer. The hydraulic vane pump was used at the expe-riment. We carried out the several experiments on the volumetric efficiencies, torque efficiencies and over all efficiencies of the vane pump used hydr-aulic oil (heavy medium), spindle oil (Spinox 2S) or water, and obtained the following results. (1) The volumetric efficiencies, torque efficiencies and over-all efficiencies of this pump were expre-ssed by the equations (6), (9) and (10) respectively. (2) The experimental values almost coincided with the values calculated from the equations (6) (9) and (10). (3) The volumetric efficiencies and the over-all efficiencies of this pump used spinox 2S or water were lower than those used heavy medium, but no significant difference in torque efficiencies was found between the three kinds of fluids. (4) In order to raise the volumetric efficiencies of this pump when using low viscosity fluids (spi-nox 2S, water), it is necessary to reduce the lea-kage loss. (5) Many experiments are necessary in addition to this experiment to apply rotary pump for power sprayer.
The pump performance and the pressure pulsation of the portable power sprayer are measured. This sprayer has one cylinder and is driven by a two cycle engine. It has not air chamber and pressure regulator, but has variable volume piston, buffer piston and safety valve. As the variable volume piston regulates the suction volume, the power requirement gradually decreases over the discharge pressure of about 20kg/cm2. As the buffer piston restrains the discharge pressure pulsation, the pressure pulsation is comparatively small at the spraying pressure of 10-20kg/cm2. The discharge pressure does not exceed over about 30kg/cm2 by the safety valve. Therefore, this sprayer can be used without the pressure regulation at the discharge pressure range of 10-20kg/cm2.
Studies on load characteristics were made of two headfeeding combines for the harvesting of paddy land rice. Both combines were epuipped with socalled head feeding threshing unit and of 50#cm cutterbar length. Power consumption of the combines was measured using the strain gauge and tachogenerator method, as written in our previous report “Load characteristics of a two-cylindered rice combine”. Power requirements of the main units of the combines, that is, cutting and transporting unit, threshing and cleaning unit, and travelling unit, was measured at various rates of crop throughput and travelling speed. The measurements have given the following results: 1) In the case of head-feeding combines, grain throughput is not appropriate as the index of the load on the threshing unit, not to say of straw throughput. The sum of grain and chaff throughput is better as the index of the load, giving better linearity between the load and power consumption. 2) The total average power requirements of a combine should be described as a sum of average power requirements of travelling unit and that of harvesting unit, which are governed by travelling speed of machine and the sum of the throughput above mentioned. This is the same result as obtained in the case of a two-cylindered rice combine. 3) Torque fluctuaticn of the head-feeding combines is far less than that of ordinary combines.
In this report, the tension of rope and twine in and after binding were measured using the binder in rice field. The tested ropes were two kinds of polypropylene and polypropylene blister ropes and jute twines. The tension at the guide tube in binding depended upon the stiffness of rope brake, but the tension at the guide pin in binding and the tension of rope on the sheaf after binding depended upon the volume and size of straws fed to the door by the packer. So the tension of rope and twine in binding were affected not only by the kinds of rope and twine but also by the conditions of straw.
The transverse vibration of a portable rotary cutter stem with an electric motor was measured under freely suspended condition. Characterestic frequencies of flexural vibration were also calculated using three simplified vibration models: (A) A simply Supported beam. (B) A free beam with concentrated mass at its each end. (C) A free beam with one concentrated mass at one end, and three concentrated mass at the other end (motor assembly's end). Results obtained are as follows; (1) Tow characterestic frequencies were found in the rotational velocity range, and the secondary one seemed to be important in practical operation. (2) The acceleration measured was rather great even at velocities far from those charactrestic frequencies, in spite of their small amplitudes. (3) The difference between the frequencies by calculation and the experimental data was as follows; Model first freq. second freq. A -8% 12% B 7% 17% C 2% 4% (4) The numerical calculation procedure seemed to be one of the best ways for determing characterestic frequnencies of portable rotary cutters by improving there models.
By employing the comparative method, the thermal conductivity of rough rice, soy beans and red beans was determined. First the thermal conductivity of a plate of glass was compared with that of distilled water whose thermal conductivity had been given by Dr. Nukiyama as equation (2) and was determined to be equation (3). Then the thermal conductitvity of the glass plate was used as the standard to measure the thermal conductivity of grains. Under the conditions of moisture contents and the bulk density given in Table 3, the thermal conductivity of rough rice, soy beans and red beans was given as shown in Fig. 4. The results are valid between 10°C and 20°C but they may be extended up to 25°C and down to 5°C with acceptable accuracy.
The anther designed a high frequency type electrical moisture meter so as to make possible automatic moisture content controls for the continuous flow grain dryer. Because this meter was too sensitive to variability of grain conditions flowing in the continuous dryer. The meter readings were very scattered. In addition, the kind and the temperature changes of grain could not be neglected. Also the meter readings were affected by the chemical components of parched grain and its bound water in addition to the free moisture of grain. Its equivalent moisture was about 4.2-4.5% of the apparent density of parched grain in the case of unhulled rice. The auther investigated these factors which influenced meter readings systematically and in the detail. The main results were the followings; 1. When the filling method was controlled, the standard deviation of the apparent density of grain in the test cell was reduces to 1/8 of the result of no controlling. Dependence of the apparent density on moisture contents was little observed. 2. The detector current I of the high frequency type electrical moisture meter of the resonance circuit method was formularized as the following to general; I=Im0Gt0[Gt2+ω2(C-L/Z2)2]-1/2 (7) Where, Gt=1/Rpc+1/Rpx+RL/RL2+ω2L2 C=C1+ΔC1+Cx Cx: The electrical capacity of grain. Rpx: The effective parallel resistance of grain. 3. In the case of C-L/Z2>0, the relation between the detector current of the meter developed and the apparent effective moisture density (a tentative name) of grain was formularized as the following; I=Im0Gt0/(a+bθ)d0s8+Im0Gt0X (21) Where, d0s=(wd+β)d2e d0s: The apparent effective moisture density, βd2e: The apparent equivalent moisture density (a tentative name) the chemical components of the parched grain and in its bound water, θ: The grain temperature. d2e: The apparent density of the parched grain, wd: The moisture ratio (dry base). 4. When the filling method was controlled, the standard deviation of the moisture content (wet base) measured with this meter was reduced to 1/3.8 of the result of no controlling. 5. The relation between the meter reading and the moisture ratio wd was formularized as the following: I=Im0Gt0/(a+bθ)(β+wd/1+wdd1e)8+Im0Gt0X (25) When the meter readings were corrected by the measurement of the apparent density of grain d1e, the standard deviation of the moisture content measured with this meter was reduced to 1/5.6 of the result of no correcting. 6. With the described the standard deviations of measurement of the moisture content were 0.29-0.24% in case of the unhulled rice in the tempering. The standard deviations were of deviations between the oven dried standard moisture contents and the ones calculated by equation (25).
The authors investigated a fluidized bed drying of cereal grains and the following results were obtained. 1. The minimum fluidizatiop velocity of unhulled rice, hulled rice, wheat, millet and soybean was 1.08, 1.04, 1.05, 0.80 and 1.28 meters per second respectively which agreed with the values calculated by Leva's equation (eq. 4). 2. When the unhulled rice was dried by fluidized bed drying, the average drying speed was about 3 percent per hour and the rate of cracking-kernels increased with drying temperatures over 40°C. However, under the drying temperature of about 30°C, the average drying speed was 2.57 percent per hour and the rate of cracking-kernels was 5 percent. 3. The drying equation for the thin layer (eq. 5) could be applied for estimating fluidized bed drying quantitatively.
The drying process of Citrus Unshu which follows the water-washing and waxing processes. was investigated and the following results were obtained. 1. The mean air velocities over the net-convyer were 2.22m/s at the present equipment and 1.33m/s at the improved one. 2. The amount of water adhered to citrus during the present washing process weighed 0.3 to 0.4 grams for Citrus Natsu and 0.08 grams for Citrus Unshu. Removal of the water during the drying process was not sufficient in either citrus. 3. The water removed from the surface of later-ripened Citrus Unshu, during drying process was 61.4 percent at the present-type-apparatus and 75.9 percent at the improved one, and 78.4 percent and 91.8 percent respectively when including the process of wax-drying, The effect of improvement was perceived. 4. Difference in quality of products was not detected between present-type-equipment and improved one. Waxing had a tendency to decelerate the decay of early-ripened Citrus Unshu, whereas to accelate the decay of later-ripened one. 5. When the wetted Citrus Unshu was dried by heated air, the result was given as the following. Q=W0(1-e-ct) where Q: weight of evaporated moisture (kg) W0: initial weight of water adhered to product (kg) t: hour (h) c: drying constant (kg/kg′·h)
Alfalea meal was compressed in the cylinder 10mm in internal diameter. Pressure-density relations and relaxation spectra were investigated by the experiment of stress relaxation. 1) Heating increased slightly the strain and density of compressed plant of meal but gave it a good solidity. 2) Pressure did not increase over a certain value and the solidity of compressed plant was bad in case of compressing high moisture content material (over about 30%) by a piston. 3) Relaxation spectra were large in case of high piston pressure, low piston speed, high moisture content and high temperature of the plant material. 4) Dimensions of relaxation spectrum of compressed plant material which was in the cylinder was influenced by piston pressure, difference between piston pressure and base pressure and friction between compressed plant material and the inner wall of the cylinder.
The effects of STP additives were tested on six engines for farm use, in which STP was added 20% to oil and 0.5% to fuel respectively. The increase of shaft horse power of engines were 4.8% (at maximum) to 0.2% (at minimum). and mean value was about 2%. The cause of these power increaments were supposed that STP maintaines a betterseal between the engine cylinder and the piston rings in high compression engine at high speed.