稻穗之物理性與小型水稻聯合收穫機工作性能之關係試驗

Tests on the Performance of Small Rice Combine Harvester In Relation to some Physical Properties of Rice

鄔清標(C. P. Wu) ； 黃光華(K. H. Huang)

《中華農業研究》 20卷4期 (1971/12) Pp. 24-46

https://doi.org/10.29951/JARC.197112.0003

摘要

1．稻穗穀粒最小抗拉強度對摩擦掉粒數之影響度Q值爲46.5%，其與穀粒含水分率之交感作用及與穗粒數之交感作用之Q值，亦各佔13%及2.5%，所以穀粒最小抗拉強度之大小對摩擦掉粒之影響極大，兩者間之關係式爲：
y=-0.14x+31.17 y：摩擦掉粒數(%)
x：穀粒最小抗拉強度(gr)
2．目前小型水稻聯合收穫機所使用之脫穀選別機構，極易受到稻葉水分含量以及稻束供給速度及供給深度之影響，所以其有各種調節裝置，使機器能適應各種情況之水稻，但由於調節裝置過繁，相互間不易使其完全配合，因此摩擦掉粒數、行車速度、水稻成熟度等因素對水稻聯合收穫機收穫作業掉粒損失之影響，往往比人爲因素小，因而各因素之F值均不顯著。
3．田間表土硬度（貫穿深度），稻葉含水分率及田區面積大小對工作能量均有顯著之影響，稻葉含水分率之影響度約佔25%，與其他兩因素之交感影響亦各佔12%及8%。
稻葉含水分率與機器工作能量之間的關係式爲：
y二0.26x+76.94 y：工作能量(min/10a)
x：稻葉含水分率(%)
表土貫穿深度及田區面積大小對工作能量之影響度各爲15%，其他機差之影響度爲20%。
表土貫穿課度與工作能量之關係式爲：
y=9.45x+76.07 y=工作能量(min/10a)
x=表土貫穿課度(cm)
田區面積大小與工作能量之關係式爲：
Y=-0.01x+100.14 y=工作能量(min/10a)
x=田區面積平方公尺
4．割切機構上所附裝之扶稻桿作業性能極佳，且割切高度及脫殼時稻束之供給深度均有良好之調節裝置，只要節調妥當，則稻株之高度、分蘗數、倒伏程度等對機器之作業性能均無太大影響，但完全倒伏之水稻即無法收割。
5．因機器之履帶高度不高，表土太軟，重錘貫穿深度超過3 cm以上時，機器之行走即不甚方便，影響工作效率，超過6 cm以上時，工作極爲困難。
6．目前之小型水稻聯合收穫機，每天工作效率平均約爲0.6公頃，但葉面有水滴時即無法工作，同時，稻束供給量稍爲過量，即隨時發生堵塞現象。故爲提高機器工作效率，目前之下方供給稻束脫穀按及風選式選別機構不甚適用，應改爲上方供給稻束脫穀法及搖動選別法之脫穀選別機構。
7．稻谷的損失率爲0.5~2%之間，損失量並不太嚴重。
8．每公頃所需總人工時數爲34小時，其中聯合收穫機正常作業所佔比例爲35%，手工刈割田邊稻佔28%，利用聯合收穫機之脫穀選別機構脫田邊稻爲37%。可知工時分配上極爲不經濟。改進的方法，惟有增大田區面積，及修改機器本身，使能免去處理田邊稻的工作。
9．機器的田間理論工作效率平均爲57%，田間有效工作效率平均爲64.9%。提高有效工作效率的方法，在於一方面使田區長邊與寬邊長度比例加大，另一方面簡化機器的結構，儘量減少調節手續。
10．每公頃所需工作成本，可以下列方程式表示之：
(方程略)式中A爲年工作面積（公頃），x爲可使用年限，因機器價格頗高，所以年工作量及可使用年限爲影響成本最大的因子。依照目前使用情形推算，年工作量爲30公頃，可使用年限爲4年，則每公頃所需工作成本爲1,780元。欲使成本降至低於1,300元，則機器必需經過售改，使操作人員減爲二員，年工作面積能在40公頃以上，耐久年限4年以上，始可達成。
11．爲降低工作成本，今後應改進的方向略如下列：
(1)將刈切部份置於脫穀部份的前端，藉以免去手割及機脫田邊稻的手續。
(2)將脫穀選別部份工作容量加大，並使之適用於雨天、露晨。
(3)加大履帶的驅動輸徑，或改良履帶的結構，使收穫機能適用於軟泥田區。
(4)簡化各部份的結構與調整，並增強其耐久性能。
(5)增加機器之機動性，以便提高其利用率。

並列摘要

1. The minimum tensile strength of rice grain significantly affected the friction loss of grain. The ”Q” value was 46.5%. The moisture content of grain and the number of grain affected the friction loss were not as important as the minimum tensile strength. The ”Q” values were 13% and 2.5% for moisture content of grain and number of grain per panicle respectively. The regression equation between minimum tensile strength and friction loss of grain is
Y=-0.14X+31.17
Where X=the minimun tensile strength of grain. (gr.)
Y=the percentage of the friction loss of grain. (%)
2. The effect of friction loss of grain, the forward speed of the combine & the degree of maturity of rice on grain loss caused by combine harvester were not significant. This would be possible that factors other than the above mentioned three were involved. For instance, the moisture content of the leaves, the feeding speed of rice bundle and the length of rice plant feeding inside the threshing machine. For the purpose of fitting and easing the handling of rice bundles under different conditions, this combine is equiped with various attachments which are so encepliated that the operator is not very easy to familiar with it and run it properly, therefore the improper handling of the combine would cause more grain loss.
3. The hardness of the surface soil or top soil, the moisture content of the leaves, and the size of working plot all greatly affected the working capacity of the combine harvester.
The regression equations for the moisture content of the leaves, hardness of the surface soil and the size of working plot with the working capacity are:
a. moisture of leaf: Y= 0.26X+76.94
where: Y=working capacity (min/10a)
X=moisture content (%)
b. Hardness of surface soil Y9.45X+76.07
where: Y= working capacity (mim/10a)
X=the depth of the weight droped into the surface soil (cm)
c. The size of working plot: Y=-0.01X+100.14
where: Y=working capacity (min/10a)
X=size of each working plot (m^2)
4. The rice pick-up attached to the cutting mechanism of the small rice combine is excellent, The rice cutting height and the length of rice plant for feeding to the threshing mechanism can be adjusted properly. Hence, if all parts are properly adjusted, these factors such as the height of rice plant, the number of rice plants per hill, and the declination angle of rice plant will not affect much on the operation of combine. However, this type of small combine won't work well when lodging of rice plants is very serious.
5. The height of the track on both side of the combine isn't sufficient. If the surface soil of the field is too soft (when a given weight is droped down from a height of one meter to the soil surface and penetrates into the surface soil by 3 cm but less than 6 cm.) combine won’t proceed well and its efficiency is very low. When the given weight penetrates into the soil by 6 cm or more, this combine won’t work any more.
6. The working capacity of this small rice combine is 0.6 hectare per day in average under normal conditions. However the capacity of this machine is greatly reduced or even won’t work when the leaves are wet. In the meantime, the threshing machine will be in trouble when more too much rice plants are fed. The combine would he efficient if the present rice feeding mechanism, which is fed under the threshing drum, be changed to feed rice plants on the threshing drum, and the wind cleaning mechanism be changed to vibrating sieve.
7. The percentage of grain loss is ranging from 0.5 to 2%, which is considered not a very serious loss of grain.
8. To harvest one hectare of rice required 34 man-7% for combine threshing the rice harvested in the border rows. Therefore, it is quite clear that the size of farm for using combine with great efficiency and better benefit is exstremely important. Because 65% of manhour required for harvesting the rice on the border row is quite unreasonable.
9. The theoretical field efficiency of the machine is 57% in average, and the effective field efficiency is 64.9% in average. The effective field efficiency can be increased if the proportion of length to width of a field is increased in order to reduce the turn of combine. the machine construction be further simplified and the regulating process be abated.
10. The following equation expressed the total cost for harvesting one hectare of rice.
Y= 81,000/AX+11,655/A+21
Where:
A= Hectare of rice to be harvested per year.
X= Fffective service life of the machine.
The high price of the machine, the acreage harversted per year and the service life of the machine affected the total cost greatly. From this test, 30 hectares of rice harvested per year, and 4-year service life will be the minimum requirements for economic use of the combine. Under this conditions, the total cost for harvesting one hectare of rice is NT$ 1,780.00. If we want to reduce the cost to less than NT$ 1,300.00, then the machine should be improved to allow 2 operators to work on, more than 40 ha. of rice be harvested per year and the service life of the machine be more than 4 years.