収穫機の研究 (29)

小型ゴンバインの試作研究 (第1報)

抄録

Since 1947 we have accumulated efforts to realize small side-delivery windrowers (Journal of the Society of Agricultural Machinary, Japan, Vol. 10-Vol. 23), one of which, HR602, gave satisfactory results and is being introduced into Japanese farming from the view point of labour saving. The windrower is simple in mechanisms and can be attached to the uni-axle tractor. The adaptability of the machine for lodged crops, however, is rather poor. This urged us to construct experimental combines though we have not got at a clear notion that how the feature of the Japanese agriculture in the future should be and that what the acreage of a single paddy field and the size of combine in the future will be. The principal objects of the construction were to make the losses of the grains as little as possible at the harvest of lodged rice and to make the machines as small as possible.
We constructed three combines in 1961, the technical specifications of which are given in Table 1, and carried out some field tests.
Though the above cited objects could not be realized for the shortage of time shared for designing and the shortcomings in mechanisms caused by the lack of fundamental data. From the experiments, however, we found out many problems which will help us in the following designing of combines. Given below are short explanations of the machines and the results of the experiments.
1) HT612 has a side delivering (L-shaped) header with a cutter bar length of 1.1m. The undershot type elevator with slatted chains was adopted, the lower shaft of which was designed to be common to that of the auger. Cleaning sieves were avoided, for the recleaning after artificial drying is an indispensable operation under Japanese climatic conditions in any case.
Thus we aimed to make the machanisms as simple as possible, but the results of field tests were unsatisfactory. A fatal defect was seen at the corner of the header auger and the slatted chain elevator.
2) HT613 has two vertical axes with a plate at the both lower ends, on each of which four knife-sections are fixed.
Belts and star-wheels were adopted instead of reel. The crop is cut and thrown on the canvas elevator by these rotary cutter head. The width of the elevator' however, was too narrow and the angle of elevation was too steep to allow a smooth flow of crops, which resulted in clogging of crops at the half way of the elevator canvas. The threshing unit of this machine is common to that of HT612.
3) HT614 is of centre-delivering type (T-type) with a cutter bar length of 1.1m. It ran fairly well, but the capacity of threshing parts was observed not to be matched to the other parts. Further improvements of the capacity will be done by the next harvest.
Standing on these experiences, we are to design six other models of small combines.