Abstract: In order to establish a collision model between seed cotton and working parts of harvester and processing machine, this paper measured and analyzed restitution coefficient of seed cotton by recovery coefficient measurement device based on kinematics equation. The restitution coefficient of seed cotton was determined for different drop numbers using a drop test apparatus with drop heights ranged from 200~400 mm, and the material thickness was ranged from 2~6 mm. The collision materials were Q235 steel, aluminum alloy, organic glass and rubber. A complex orthogonal design of L8(41×24) was conducted to systematically investigate the above factors effected on restitution coefficient of ‘Zhongmian 6913’ seed cotton, harvested by brush-roller type stripper cotton harvester. The single-factor experiments were carried out under the condition of different collision materials, material thicknesses and drop heights. The results showed that the significance of above factors to restitution coefficient of seed cotton were collision material > drop height > material thickness > seed cotton number. Among them, the seed cotton number had non-significant effect on restitution coefficient. The results of single-factor experiment indicated that the order of recovery coefficient between seed cotton and collided materials was Q235 steel> aluminum alloy> organic glass> rubber. In the test scope, the restitution coefficient of seed cotton decreases almost linearly with the increase of drop height, and firstly increase significantly then slowly with the increasing thickness of collided material. The above results might provide theoretical references for rational design and simulation of seed cotton harvester and related important working parts.

Key words: collision test, kinematics, restitution coefficient, seed cotton

摘要： 为建立籽棉与其收获及处理机具工作部件间发生碰撞时的碰撞模型，采用基于运动学方程的恢复系数测定装置，对籽棉恢复系数进行测定及分析。不同下落次数的籽棉恢复系数通过下落实验进行测试，实验装置下落高度范围200～400 mm、材料厚度2～6 mm，考察材料为Q235钢、铝合金、有机玻璃和橡胶的碰撞。针对含水率为12.54%的“中棉6913”籽棉品种，采用L8(41×24)混合正交试验方案研究碰撞材料、材料厚度、自由下落高度和籽棉个数四因素对籽棉恢复系数的影响，然后针对碰撞材料、下落高度和材料厚度进行单因素试验，并获得下落高度和材料厚度对恢复系数的影响规律及回归方程。试验结果表明，影响籽棉恢复系数因素的显著性顺序为：碰撞材料>下落高度>材料厚度>籽棉个数；其中籽棉个数对恢复系数影响不显著。由单因素试验结果可得：籽棉与碰撞材料之间恢复系数顺序为：Q235>铝合金>有机玻璃>橡胶；在试验范围内，籽棉恢复系数随着下落高度的增加而近似线性减小；随碰撞材料厚度的增加先呈显著增大后缓慢增大。上述结果可为籽棉收获及处理机具中相关工作部件的合理设计及籽棉与机构联合仿真提供理论参考。

关键词: 碰撞试验, 动力学, 恢复系数, 籽棉