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32 巻, 1 号
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1970 年 32 巻 1 号 p. 1
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーPDF形式でダウンロード (223K) -
水平けん引特性芝野 保徳1970 年 32 巻 1 号 p. 2-9
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーThe horizontal traction performances of walking tractor were compared on road and cultivated land. In the tests, the tractive forces, the travel speeds, the torques and revolutions of wheel shaft and the loads on the driving wheel and steering handle were measured at different load on the driving wheel and travel speeds. The experimental results which were obtained in the way described above were shown in the nondimensional parameters (the coefficient of traction; μ, the coefficient of driving force; μt, the coefficient of weight transfer on the driving wheel; k, the coefficient of rolling resistance; ρ, the force ratio; ν, the tractive power coefficient; π, the tractive efficieney: η and the travel reduction; s). The characterietics of the horizontal traction were summarized as follows.
(1) Both the tractive forces and tractive powers increased when the loads on the driving wheel were heavier on road and cultivated land, but it was recognized that these experimental values were agreed when the experimental results were shown in the nondimentional parameters.
(2) The traction performance on the road was better than that on the cultivated land because the rolling resistances on the cultivated land were lager than those on the road.
(3) As an example, the nondimentional factors at the travel reduction of 0.3 on the cultivated. land were as follows: μ=0.62, μt=0.85, k=-0.19, ρ=0.22, ν=0.73, π=0.44, η=0.52
(4) On the cultivated land, the tractive power coefficient became maximum of 0.44 at the coefficient of tration of 0.62 (the travel reduction 0.28), and the tractive efficiency became maximum of 0.57 at the coefficient of traction of 0.43 (the travel reduction 0.17).抄録全体を表示PDF形式でダウンロード (1309K) -
動的沈下伊藤 信孝, 増田 正三1970 年 32 巻 1 号 p. 10-15
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーThere are very few studies on the relation between running speed and rolling resistance of vehicles. Even though the running resistance of vehicles has been studied for a long time, especially in the field of automobile engineering, it is only known experimentally, using the method of costing performance test. In this paper the behavior of tractor wheels, especially the dynamic sinkage of tractor wheels (or vertical defomation of tires) is discussed theoretically.
The sinkage of wheels is very important when considering the running resistance which interrupts travel. The purpose of this study is to find the relation between sinkage of vehicles and running speed, and to apply the results to classify the soil characteristics which will give some effects on trafficability of tractor. It can also be applied to fluid mechanics in the same way.
In the field of automobile engineering, a coasting test is held very often to estimate the performance of the car by deriving the coefficient of rolling resistance. However, it is very diffictlt to apply this method on heavy work machines such as tractors.
Assuming that the tractor is running at constant speed v0 (initial speed), the same depth of sinkage will be kept on homogeneous soil. Substituting the normal running speed v into the initial speed v0 in costing test, hd (dynamic sinkage) is hd=v2/2gc
Total sinkage (or vertical displacement of tire) is expressed as the summation of hs and hd.
Measurement items are:
(1) tractor velocity
(2) static sinkage, hs
(3) dynamic sincage, hd
(4) total sinkage, ht
Total speed was obtained by measuring the time in which the tractor ran more than 5m. Static sinkage hs and total sinkage ht were gotten with a measure and hd was calculated from the equation ht-hs.
To have an experimental proof of this theory with high accuracy, there are some difficulties such as the necessity of much soil which has the same property and wide area as the test field. Generally, as soil is not homogeneous, many errors will be involved in measurement. If the experiment will be held with a pretty high accuracy it is very useful for results to classify the soil variety and its characteristics.
In this paper, the dynamic sinkage (deformation of tire) is not so important when the tractor runs, but from the view point of classification of soil which can be applied to the trafficability of tractor and the similarity to the fluid mechanics, because the dynamic sinkage (or deformation) phenomenon will be similar to the head loss of the fluid flow in the pipe which has different areas at both ends.抄録全体を表示PDF形式でダウンロード (825K) -
松山 龍男, 川崎 健, 前岡 邦彦1970 年 32 巻 1 号 p. 16-22
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーThe angles of static and dynamic side-overturning of two wheel walking tractors were measured to clarify the limit of their utilization on slope land.
The results obtained were as follows;
(1) The authors divided the dynamic angle into two categories, according to the degree of operating muscular strength on handles of tractor:
a) αdmax, with maximum muscular strength enough to control overturning; b) αdmin, with loose grip.
(2) The static side-overturning angles αs in various types of tractors were obtained in the following simple approximate formula: αs=0.51d where, d is tread of tractor in cm.
It was proved in recent tractors that the angle αs increased with size of tractor, ranged from 15° to 40°, and does not exceed 40°.
(3) The angle αdmin was independent of tractor weight, and associated with such factors as travel speed V(m/s), tread d(cm), height of an obstacle H0(cm) and αs(°). In case that a contour travelling tractor crosses over a convex obstacle with uphill wheel, the relation mentioned above is expressed in the from:
αdmin=[1-sin-1{H0+γH0mVn/d}/αs]αs
where, m, n and γ are constants shown in table 4.
(4) The two wheel walking tractors on market have dynamic side-overturning angles of about 15°-20° in case of contour travelling, and are considered to be unsuitable for utilization on steep land because of unstability.抄録全体を表示PDF形式でダウンロード (1059K) -
プレートシールド使用時の一般特性小松 実1970 年 32 巻 1 号 p. 23-27
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーWhen tilling is done, not only the rough-tilling, but having in mind all or a part of the procedure satisfying the condition as a seedbed, the author defines it as the seedbed making tillage. The results of test on the characteristics of rotary tillage using are as follows:
1) Restricting the initially tilled soil within the revolving locus circle of the tillage tine by the action of shield, thereby giving multi-tillage tine action to the soil, it was recognized that the pulverizing effect, stub-cutting performance, and ground leveling were improved.
2) In this experiment, the amount of the restricted soil was controlled by shield angle α measured from the plane normal to the direction of travel. As α was decreased, the soil clods became fine as a whole, the stubs were chopped to pieces, and the degree of the surface leveling became very high.
3) The average weight diameter (Dw-2) of the best soil pulverizing in the practical region was 18.8mm. In this case it was shown that Dw-1/Dw-2=2.4, Psn/Pso=2.6, and compared with the soil pulverizing done by making the pitch of thee ordinary rotary tiller small, the pulverizing efficiency was extremely higher.
4) The relation between soil pulverizing resistance Pk and pulverized soil diameter Dwo=Dw-1-Dw-2 is Pk=a. Dwon, and the relation between specific resistance of soil pulverizing K and tilling pitch Pi is K=a.Pi-n.
5) The larger the initial average weight diameter Dw-1, the easier the pulverizing and the more amount of the pulverized soil. Generally, from the neighborhood of Dw-2 is 20mm, K begins to increase suddenly.
6) The tilling performance was similar to that of the common rotary tilling, but substantially both the rotor horsepower and wheel axle horsepower became larger.抄録全体を表示PDF形式でダウンロード (881K) -
散布性能とトルク特性伊佐 務, 木谷 〓, 市川 真祐, 永吉 哲義1970 年 32 巻 1 号 p. 28-35
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーThe distribution pattern of a centrifugal ditributor was measured. The test results were compared with the theoretical calculation. The main results were the followings;
(1) The test results in the field showed that the uniformity of the distribution was good. The effective width was, however, much smaller than the distribution limits (or the maximum width).
(2) Assuming that the air resistance was acting only in the horizontal direction, the distribution limit was calculated. The calculated values showed good agreement with the test results.
(3) The stationary distribution test proved to be very effective for broadcasiting tests of fine particles. This test method was very efficient and accurate.
(4) The compaction of lime due to vibration resulted in a rapid increase of torque. A series of tests led to an empirical equation.
(5) Eight factors which composed total torque were analysed. From a set of tests on various combination of these factors, a system of linear equations was obtained, which gave the values of the torque factors.
(6) Based on the calculation of the particle pressure in the hopper, the agitator torque and the spinner torque due to the shearing and friction of lime were calculated. The calculated values agreed fairly well with the test results抄録全体を表示PDF形式でダウンロード (1162K) -
麦刈取時の各部所要動力松尾 昌樹, 牧園 晴充, 太田 善三郎1970 年 32 巻 1 号 p. 36-42
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーFrom the experiments of wheat harvesting by three-row type walking grain binder, the following power requirements of each part of it were obtained:
(1) The torque of driving wheel and binding unit was constant independently of wheat feed rate (kg/sec), those of pick-up unit and conveyor were linearly increased and that of cutting unit was slightly decreased with the increase of wheat feed rate.
(2) When the density of planting of wheat was low, the net torques of each part were relatively small compared with their no-load torque.
(3) The torque of driving wheel was relatively large compared with the other parts.
(4) When the what feed rate was 0.25-0.45kg/sec the total power requirements were 0.6-1.15 PS at packing, and 1-1.8 PS at binding in the first gear, and they were 0.5-0.9 PS at packing and 0.8-1.4 PS at binding in the second gear.
(5) The total power distribution rate was in the following orders: at packing, driving wheel (31-40%)>pick-up unit>cutting unit>conveyor>binding unit (4-10%), and at binding, binding unit (39-42%)>driving wheel>pick-up unit>cutting unit>conveyor (10-11%). Binding unit power rate at binding was relatively high.
(6) Even if wheat feed rate was the same, the power requirement in the second gean (high traveling speed, low revolution) was considerably small and economic compared with the power requirement in the first gear (low traveling speed, high revolution).抄録全体を表示PDF形式でダウンロード (1010K) -
スローワによる茶葉の損傷中川 健治, 杉野 公一, 堀部 和雄1970 年 32 巻 1 号 p. 43-46
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリー1. Using the different shapes and structures of impellers, the extent of tea-leaf injuries made by the thrower while being conveyed was investigated chemically and physically. Tea-leaves were harvested in several seasons and at several stages of growth.
2. The rate of damages of leaves rose with the increase of throw speeds. The relation among the damage degree Y (%), the revolution number N (rpm) and the throw speed V (m/s) of impeller was shown by following formulas in the range of this experiment.
Y=4.3×10-7N2.64
Y′=8.1×10-3N2.64
The damage degree increased with the power of speeds which was between 2 and 3. Therefore lowspeeds were desirable for the economy of power and damage reduction. The increase of damage was within 3% at normal revolution speeds
3. Observing the relation between wings structure and tea-leaf damages, the presence of mat and nylon wire brushes in the first cut tea leaves, and of brushes in the third-cut ones, was very effective to reduce the damage. But wings shape and carring capacity per hour had little to do with it.
4. If the structure and use of thrower, handling of tea-leaves are proper the quality of products does not necessarily go down by conveying tea-leaves within normal throw speed. Threfore this thrower may be successfully employed as a carrying system of tea-leaves.抄録全体を表示PDF形式でダウンロード (688K) -
中馬 豊, 村田 敏, 紀伊 富夫1970 年 32 巻 1 号 p. 47-52
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーThe impact acceleration of apples on the impact board by “drop test” was measured and recorded with a synchroscope employing strain-gage type accelerometer. The experiment proved that the calculated maximum impact acceleration of Hertz's theory for elastic body agreed with the observed acceleration. The Hertz's theory was extended to the case of carton-boxed apples. The experiment showed that the calculated acceleration was greater than or equal to the observed value because of the random movement of the apples and the random impact of the bottom board of the carton box, and the calculated acceleration gave the possible maximum limit. The minimum acceleration of 45 G was obtained to damage the apple by observing the cutting section of the impactedpart of applee.抄録全体を表示PDF形式でダウンロード (6468K) -
鹿児島大学可搬式真空冷却装置の負荷特性と各種産物の冷却特性試験石橋 貞人, 小島 孝之, 御木 英昌1970 年 32 巻 1 号 p. 53-58
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーAt first, the load test of the portable vacuum cooler reported on the part (1) was run using water in a plastic container in stead of agricultural products. Then, vacuum cooling tests were run on various agricultural products, and the characteristic cooling properties were obtained.
The results were as follows:
1) With the coil condenser, the refrigerator required a large cooling capacity especially during a short period after the flash point, and then the cooling load of the refrigerator decreased (Fig. 6). Little water vapor reached the pump, because 90-98% of vapor was frozen and caught by the coil condenser.
2) With the ice condenser, HAKUSAI (Chineese cabbage) was cooled safely and uniformly, although the vacuum pump could not reduce the operational pressure below 6mmHg and temperatures below 3°C were not readily obtained.
The ice condenser caught 80-90%, of water vapor. For a larger condensing capacity than the above the required quantity of crushed ice in the ice condenser box may be at least 3-4 times the total heat load of products.
3) Leafy products such as lettuce, HAKUSAI, spinach, celery, etc. were proved to be best suited for this type of precooling. Also vacuum cooling was efficient for strawberry, Holland pea (a field pea), sweet corn and mushroom.抄録全体を表示PDF形式でダウンロード (3362K) -
トマトの生育, 成熟および貯蔵中における機械的強度変化石橋 貞人, 小島 孝之1970 年 32 巻 1 号 p. 59-64
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーIn 1958, this experiment was conducted on mechanical properties of tomatoes (FUKUJU NO. 2) during growing, ripening and storage.
A series of compression creep and relaxation tests was run at 10mm/min. on a commercial testing machin, the Tensilon Model UTM-4 (Fig. 1 on the part 14), with a flat disk 6mm in dia meter plunger and a disk 150mm in dia meter. to measure certain mechanical properties of it.
The following tendencies were found.
1) Rupture force of tomatoes by plunger compression continues to decrease during growing, ripening and storage, but the amount of deformation upto the rupture point continues to increase.
2) Toughness of tomatoes tends to be the largest at about the harvest time throughout the period of growing, ripening and storage.
The higher storage temperatures, the faster the over-ripening rate.
4) In creep and relaxation tests, the behavier of the products could be represented by a 4-element model with springs and dashpots.
5) Unripening flesh had such large viscocity that the recovery in creep and recovery test was conducted perfectly, and was disregarded. η3 Therefore, the behavier of green flesh in relaxation test also might be represented by a 3-element model (Fig. 9-a).抄録全体を表示PDF形式でダウンロード (898K) -
今野 博1970 年 32 巻 1 号 p. 65-70
発行日: 1970/06/01
公開日: 2010/04/30
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1970 年 32 巻 1 号 p. 71-72
発行日: 1970/06/01
公開日: 2010/04/30
ジャーナル フリーPDF形式でダウンロード (394K)
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