Authors

Abstract

During the mechanical harvesting of rapeseed, the impact of the rotating reel tine on rape can easily cause the pods to burst and seeds drop. In order to determine the resistance value for low-loss harvesting of the reel, the impact force on the rape was analyzed through the measurement and wireless transmission of stress change of the tine. A two-degree-of-freedom (2-DOF) collision tester of pod resistance for field testing was designed. The results of the shatter resistance index (SRI) under 2-DOF method and the cracking force under ripping method were compared. According to the results of SRI, cracking force and tine impact force, the expected field SRI was determined. The results show that the tine impact forces at the low reel speed of 18 revs min-1 was 1.76 N. The 2-DOF method results are reliable and the SRI is significantly correlated with the cracking force. The SRI should be over 0.576 to be greater than the impact force under the low reel speed, however, only 14.8% of the tested varieties could satisfy. It indicates the resistance of the commercial varieties is generally poor and need to strengthen. The research provides a reliable reference for variety selection

Abstract in English

油菜机械联合收获中，拨禾轮弹齿对油菜造成的打击很容易使角果炸裂和种子掉落。为了获得适于低损失收获的角果抗裂角性大小，通过对收获过程中弹齿应力变化的测量和无线传输，分析了其对油菜的碰撞力；设计了便于田间检测角果抗裂角性的二自由度随机碰撞仪，并将该方法测得的抗裂角指数（SRI）与拉裂法下的开裂力结果进行了比较；根据SRI、开裂力和碰撞力结果，得到机械收获期望的SRI大小。结果表示，在拨禾轮低速旋转18 rev min-1下，对应的弹齿碰撞力为1.76N；SRI结果与开裂力间有显著的相关性，说明两自由度碰撞方法结果可靠；满足拨禾轮18 rev min-1下收获要求的角果抗裂角指数应大于0.576，所测品种中仅有14.8%满足此要求，这说明目前市场油菜品种的抗裂角性还是普遍较差，需加强品种的选育。本文为油菜品种筛选提供了可靠的参考依据。