Experimental Study on Two-Sided Loosening Shovel of Digging-Pulling Cassava Harvester

Abstract

Cassava is one of the world's top three tuber crops, and its harvesting mechanization level is low. Digging-pulling cassava harvester is the main research direction of cassava harvesters. However, the soil-loosening components of the existing digging-pulling harvesters have poor loosening effect, high tuber damage rate, and large pulling force of cassava tubers after loosening. The two-sided loosening shovel that digs and loosens the soil on both sides of the tubers has low working resistance and is not easy to damage the tubers, but there are few reports on the impact of its operating performance. Therefore, this study focuses on three common types of two-sided soil-loosening shovels: the offset-wing shovel (OWS), L shovel (LS), and double-wing shovel (DWS). A two-factor, three-level orthogonal experiment is conducted, taking tillage depth (h) and shovel distance (b) as variables, then range analysis and factor impact analysis are carried out. Finally, through comprehensive comparison and optimization, a shovel type with best operational effects and its optimal working conditions are identified. The results show the LS demonstrated optimal performance when the breakage rate and pulling force were minimized. At the optimal combination of h of 0.25 m and b of 0.6 m, the LS has a breakage rate of 7.576% and a pulling force of 291.608 N. This study can provide basis for optimizing the design of loosening parts of digging-pulling cassava harvester.