4YZT-2型自走式鲜食玉米对行收获机设计与试验

为解决国内鲜食玉米收获机械化程度低,玉米种植户劳动强度大的问题,该文设计了适应中国鲜食玉米小地块种植规模的收获机。由于鲜食玉米特殊的采摘条件,该机摒弃了传统摘穗模式,通过斜辊掰穗,完成鲜食玉米自上而下的掰穗过程,以降低对玉米果穗作用力,使果穗从茎秆上分离下来,实现了对脆嫩玉米的收获要求。为验证机器性能的可靠性、实用性,进行了田间试验,以摘穗台高度40～55 cm、拉茎带转速450～600 r/min、掰穗辊间隙25～34 mm作为试验因素对喂入姿态成功率和果穗损伤率进行三因素四水平二次回归正交试验;采用极差分析和方差分析对各因素的影响显著性进行判断,得出各因素对喂入姿态成功率和果穗损伤率的影响显著性顺序分别为:夹持拉茎带转速摘穗台高度掰穗辊间隙和夹持拉茎带转速掰穗辊间隙摘穗台高度。各试验因素最优化参数组合为摘穗台高度47.5 cm,夹持拉茎带转速525 r/min,掰穗辊间隙29.5 mm,在该组合下茎秆喂入成功率为81%,果穗损伤率为5.4%。将对应参数进行试验验证,得到优化后最佳工作参数下:茎秆喂入成功率为83%,果穗损伤率为4.7%,优化预测模型可靠。该研究可为玉米收获机械化提供技术路线,其摘穗方式可为其他类型的玉米收获机研发提供参考。

Design and experiment of 4YZT-2 type self-propelled fresh corn double ridges harvester

Abstract: With the expansion of fresh corn planting scale, the supporting agricultural machinery has not been developed correspondingly. At present, manual harvesting is still the main harvesting method in most areas, resulting in low harvesting efficiency and difficulty in meeting market demand. Aiming at that, a harvester adapted to the scale of fresh corn cultivation in China was designed in this research. Simultaneously, due to the special picking conditions of fresh corn, instead of the traditional ear picking roller or pulling stem plate picking platform, the ear breaking process of fresh corn from top to bottom was completed by oblique ear picking roller, so as to reduce the pressure on corn ear and separate ear from stem. Furthermore, through the method of special picking process, the 4YZT-2 type self-propelled fresh corn double ridges harvester was designed, which was mainly composed of ear picking platform, corn ear conveyer, hydraulic power device, diesel engine power system, travelling device and ear collecting box. Subsequently, field experiment were carried out in order to verify the reliability and practicability of harvester. The height of the picking platform, the speed of clamping and pulling stem belt, and picking roller gap were used as test factors to carry out the regression orthogonal test. The stem feeding success rate and the ear damage rate were taken as experimental evaluation index to test the machine performance. The results showed that the order of the factors affecting the stem feeding success rate was as follows: the speed of clamping and pulling stem belt, the height of the picking platform, and the picking roller gap; The order of the factors affecting the ear damage rate was as follows: the speed of clamping and pulling stem belt, the picking roller gap and the height of the picking platform. The analysis of variance and response surface was obtained using Design-Expert 8.0.6 to verify the correctness of the range analysis. Ultimately, the significance order in the range analysis was proved consistence with that from variance analysis. Moreover, the influence of each factor on the ear damage rate was extremely significant (P<0.01). The optimal parameters were 47.5 cm for the height of the picking platform, 525 r/min for the speed of clamping and pulling stem belt, and 29.5 mm for the picking roller gap. The stem feeding success rate was 81%, and the ear damage rate was 5.4%. The corresponding parameters were tested and verified in another field experiment, and the corresponding results of the two performance evaluation indices under optimized working parameters were obtained: with the stem feeding success rate of 83%, and the ear damage rate of 4.7%. The study provided a technical support for the mechanization of special corn harvesting, and its picking method also can be a reference for the development of other types of corn harvesters.