Sumitaka Kashiwagi

Fundamental Studies on Transportation System of Plant Cultivation Trays. The Tractive Force to Move a Cultivation Tray.

As the first step to establish the transportation system for cultivation trays on the ground, tractive resistance in various moving conditions was measured. The cultivation tray weight were changed from 0.57 to 1.20 kN and the effects of castor type and number, tractive velocity, ground surface type were considered. In every moving condition, the tractive resistance increased lineally with the increase of the cultivation tray weight. The ratio of the tractive resistance against the tray weight ranged 5 to 6 percent for the wheel castor and 5 to 13 percent for the ball castor. The increase of the tractive resistance was thought to be caused by the influence of the sliding friction between castor and the ground surface. The tractive resistance was not influenced by the tractive speed. For the wheel castor, the number of the castors has no influence on tractive resistance, while for the ball castor the tractive resistance showed larger with the lower number of castors.The tractive resistance showed the maximum value at the starting point of the trays, being about 1.3-1.7 times larger than the mean tractive resistance.