The writer made analytical studies on the load and harrowing characteristics of both the spur-lugged and the spiral-lugged rotors as puddling mechanism in order that their modal characteristics may be made clear and that their working conditions, together with the technical data for the development of new designs, may be defined. (1) The power consumption in paddling per unit working width and per section increases as the slippage rate and the velocity rise. This increase is expressed by a logarithmic equation, y=axb. In the case of a heavier small-type tractor, effective puddling should be accompanied by an appropriate increase in slippage. (2) The puddling resistance decreases in logarithmical proportion as the slippage rate increases. The puddling resistance of spur-lugged rotors is less than that of spiral-lugged ones. The harrowing effect of both types, however, is not satisfactory because their slippage is not large enough. (3) The power consumption and the harrowing index of spur-lugged rotors are greater than those of spiral-lugged ones. At the lower speeds, wide difference in the harrowing effect was observed between the upper and the lower profiles. (4) The curve of the hardness-depth of tilth is almost a straight line, showing that the effect of harrowing is becoming less in a lower profile.
The compararive tests of track laying device and pneumatic tire for small garden tractor (Tiller) were done on the hard well-packed ground and pulverized soil. The maximum tractive force of tiller showed 2.5 times on the hard well-packed ground, 3.2 times on the pulverized soil and the maximum coefficient of tractive force increased 0.46 times on the hard well-packed ground, 0.87 times on the pulverized soil if the tiller were attached with heavy track-laying device instead of pneumatic tire. However, the rolling resistance of tiller attached with track-laying device was higher than that attached with pneumatic tires. And the handling of the tiller attached with track-laying device was more difficult.
The vertical soil pressure caused by the driving force of tiller was measured by strain gage soil pressure cell. The results of the tests were as follows: (1) The peak of soil pressure did not appear at the positin where the center of wheel was on the center of cell but it appeared after the wheel passed across the cell. (2) Increasing the pull of tiller, decreased the soil pressure up to about 20% slippage of wheel and increased the soil pressure above 20% slippage. (3) The distribution of soil pressure was not symmetrical but it was inclined backward. (4) The horizontal soil pressure should be measured as well as the vertical soil pressure was measured for studying on the relation bettween the soil pressure and pull.
Although there are many reports on the experiments about farm tractors, but not yet systematic mechanics of traction mechanism is established, because those experiments were drawbar-pull tests for practice, not for mechanical analysis. These studies are fundamental studies on the traction mechanics of farm tractors and their hitches. In this report 1, as fundation of these studies, statical anaysis of the traction type four wheel farm tractor is presented 1 by introducing new ideas, such as, the critical hitch height and the critical pull angle, and a new calculation formula for required engine horsepower for the tractor which is engaged drawbar-pull on the grades. According to this study, following conclusions are obtained; 1) The weight transfer should be confined to the relative change in vertical soil reactions against to the traction wheel and steering wheels, accordingly the vertical component of drawbar pull is excluded from the weight transfer term. 2) The maximum drawbar pull Pm is confined by following three conditions; a) the magnitude of engine horsepower and b) reduction ratio of power transmitting gears, c) stability of the tractor. 3) The maximum drawbar pull Pm changes its magnitudes according to the hitch height and pull angle and reaches its maximum at the critical hitch height y and pull angle. 4) From the standpoint of stability of tractor, the hitch height and pull angle should not exceed their critical points. 5) In order to use the weight of tractor for drawbar pull effectively, the weight transfer be increased to its maximum.
The influences of various cooling conditions on the distribution of cylinder temperature of Knapsack type mist-duster engine were investigated, and the following results were obtained. (1) Cylinder temperature rises with the increases of r. p. m. and load, and is low on the sides of inlet of cooling air [0°] and suction [270°], and is high on the sides of exhaust [90°] and derivery of cooling air [180°]. It must be cautioned that the cylinder temperature on the exhaust side rises higher than 190°C at the 40 percent partial load. (2) Cylinder temperature at the lower partial load is much influenced by the fuel consumption regardless of the ratio of oil to gasoline mixture. (3) The slackness of fin cover by 10mm results in the higher cylinder temperature by 6°C than ordinary set, especially remarkable on the side of the exhaust. (4) Temperature rises by 27°C at thee cylinder head and decreases by 5°C at the cylinder wall due to the cylinder head fitted faultily, crosswise the direction of inlet cooling air. (5) Temperature rises by 6-7°C at the cylinder wall and by 14°C at the cylinder head due to the adhesion of dust particles, 40 to 60 gr. of Bentonite, and extremely reaches 200°C by using 100 gr. of Ceressan-Lime mixture at the 40 percent partial load. (6) Cylinder temperature rises remarkably due to the blockage of the path of cooling air on [270°C] side, while its rising is seen only at the outlet of cooling air due to the blockage of the path of [90°] side.
1. We have intended to design some sprinkler-heads which are simpler in the construction and easier in handling, and which sprinkle water more uniformely over the entire area of the irrigation, in comparison with other types of head. The authors named these sprinkler-heads “ARM-TYPE.” 2. The effects of the Arm-type sprinkler-heads on the distribution of water over the area of the irrigation were investigated on the water pressure, nozzle diameter and the angle of the inclination of the sprinkler arm. 3. In judgement, VA-3 type head is the best of all, VL type the next and followed by V A-1 and VA-2 type.
The relation between the pressure of fertilizer on the bottom of the vessel (P) and the height of fertilizer filled in the vessel (H) can be shown in the following equation. log P=log+cHlog b (1) a, b, c: coefficients determined by fertilizer The unit-weight and collapsibility of fertilizer are the positive factors which increase P, and aggregation and friction of fertilizer to the inside wall of the vessel are together the negative which decrease P. P is determined correspondently by such factors as above mentioned, that the fluidity of fertilizer can be assumed by how P relates to H. In addition, c in equation (1) almost indicates the degree of aggregation of packed fertilizer.
During three years, from January 1959 to July 1961, we have made and tested four models of flail-type forage harvester, namely FH591, FH602, FH603 and FH611. These flail- type harvesters are made to be mounted on a small type tractor. Model FH591 is equipped with four straight arms or four (or eight) curved arms cutting unit. The swath is 300mm, and its locus diametre is 600mm. Model FH611 has twelve free swinging knives with 400mm swath and 500mm locus diametre. In adition to the cutting unit, model FH602 and FH603, have auxiliary fan at the rear side of the discharge pipe and the inclination of the discharge pipe of model FH602 can be adjusted. Three tests have carried out, namely:- (a) harvesting test under field condition, (b) power consumption test, to cut and blow out the materials, (c) measuring test of the air speed in the discharge pipe, and we have come to the following conclusions. 1. Grasses such as radino-clover or orchard-grass can be harvested with these machines satisfactorily. Soiling soy-bean can also be harvested successfully with less residue left on the field than when it is cut by rotary mower, although dent-corn can not be harvested satisfactorily with 300-400mm swath. 2. Though the length of cut is much less uniform than it is with conventional ensilage cutter, it is considered that the harvested grass is suitable for silage. 3. The power consumption of the cutting unit of these machines to cut and blow out soy-bean is computed 3-4 horse power, with the yield of 2-3 tons per hour and these machines mounted on small tractors will be able to load grasses, approximately 0.5 ton per hour, under field condition. 4. Knives fixed on rigid arms are superior to that of free swinging type, in cutting hard materials, such as ripe stalk of dent-corn, but they wear out more rapidly and the safety precaution is to be desired 5. With auxiliary fan installed the power consumption, on noload, is larger than without auxiliary fan, but the desired rpm of knife can be reduced, with satisfactory result. It is difficult to differentiate the power consumption between, with and without auxiliary fan, under actual field work.