轴向滚筒式鲜食玉米脱粒装置优化设计与试验

Optimized Design and Test of Axial Roller Fresh Corn Threshing Device

摘要:

针对我国鲜食玉米机械脱粒过程中存在籽粒破损率高的问题，在已有脱粒装置结构的基础上，设计一种“柔性陀螺辊型 + 轴向滚筒变径脱粒”组合式的柔性变径脱粒装置，以实现高效脱粒。在鲜食玉米果穗力学特性研究基础上，采用包切的设计理念，建立果穗力学模型并进行理论分析，同时针对鲜食玉米脱粒装置的核心脱粒部件进行有限元仿真分析，确定影响脱粒性能的主要因素。根据理论分析和仿真结果设计脱粒样机，开展脱粒性能试验。利用Design-Expert软件设计三因素五水平二次回归正交旋转组合试验，以滚筒转速、陀螺辊转速和转轴轴距作为试验因素，以籽粒破损率、果穗未脱净率作为试验指标。结果表明: 对籽粒破损率影响最大的因素为转轴轴距，对果穗未脱净率影响最大的因素为滚筒转速;根据回归方程模型，最优组合为：滚筒转速106.630 r/min、陀螺辊转速230.001 r/min、转轴轴距54.00 mm。在此最优组合下根据实际工况开展验证试验，经3次平行试验得到实际籽粒破损率为（4.956±0.152）%、果穗未脱净率为（4.158±0.085）%，与预测值籽粒破损率5.033%、果穗未脱净率4.303%相差在5%范围内，与参数优化结果基本一致，满足鲜食玉米脱粒要求。该研究可为鲜食玉米脱粒装备优化设计和选择提供技术支持。

Abstract:

Aiming at the problem of high kernel breakage rate in the mechanical threshing process of fresh corn in China, on the basis of the existing threshing device structure, a “flexible gyroscopic roller + axial drum reducer threshing” combination of flexible reducer threshing device was designed to achieve high efficiency threshing. On the basis of the mechanical characteristics of fresh corn cob，the design concept of package cutting was adopted to establish a mechanical model of cob and carry out theoretical analysis, and finite element simulation analysis was carried out for the core threshing parts of the fresh corn thresher to determine the main factors affecting the threshing performance.According to the theoretical analysis and simulation results, the threshing prototype was designed，the threshing performance test was carried out. Design-Expert software was used to design a threefactor, five-level quadratic regression orthogonal rotary combination test, with drum speed, gyro roller speed and rotor axis distance as the test factors, and grain breakage rate and cob failure rate as the test indexes. The results showed that the biggest influence factor on the grain breakage rate was the axis distance of the rotary axis, and the biggest influence factor on the maize ear uncleaned rate was the drum rotational speed;according to the regression equation model, the optimal conditions were predicted as follows：drum rotational speed was 106.630 r/min, gyro roller rotational speed was 230.001 r/min, and rotary axis distance was 54.00 mm. The verification test was carried out according to the actual working conditions under the optimal conditions. After three parallel tests, the actual kernel breakage rate was （4.956±0.152）% , and the cob not stripped rate was （4.158±0.085）%, which was within 5% of the predicted kernel breakage rate of 5.033% and cob not stripped rate of 4.303%, which was basically in line with the optimization of the parameters and met the requirements of fresh corn threshing. The research result can provide technical support for the optimal design and selection of fresh corn threshing equipment.