摘要
为减小谷子茎秆切割力、降低切割功耗,设计了茎秆往复式切割试验台,对谷子茎秆进行不同收获时间、茎秆部位、切割器组合形式、切割倾角、刀片斜角、平均切割速度和茎秆喂入速度的单因素切割试验,并在单因素试验基础上对平均切割速度、切割倾角和刀片斜角3个因素进行响应面试验。单因素试验结果表明:收获期茎秆极限切应力、单位面积切割功耗随含水率的增大而减小;基部起茎秆极限切应力、单位面积切割功耗总体上随茎秆高度的增加而减小,茎秆茎节极限切应力、单位面积切割功耗较茎秆节间大;茎秆双支撑切割形式较单支撑切割形式极限切应力、单位面积切割功耗小;切割倾角0°～20°时,茎秆极限切应力、单位面积切割功耗随切割倾角的增大先减小后增大;刀片斜角0°～48°时,茎秆极限切应力随刀片斜角的增大而减小,而单位面积切割功耗先减小后增大;平均切割速度0. 5～1. 5 m/s时,茎秆极限切应力、单位面积切割功耗随平均切割速度的增大呈先减小后平稳变化的趋势;茎秆喂入速度对切割力学特性无显著影响。响应面试验结果表明:试验因素对茎秆极限切应力、单位面积切割功耗影响的主次顺序为平均切割速度、刀片斜角、切割倾角,且最优切割参数为:平均切割速度1. 19 m/s、切割倾角7. 2°、刀片斜角36. 4°,最优参数下茎秆极限切应力和单位面积切割功耗分别为2. 88 MPa、22. 38 m J/mm^2,验证试验值与预测值相对误差不超过3. 5%。刀片斜角对比试验表明:刀片斜角36. 4°较30°(标准Ⅱ型动刀)切割谷子茎秆时,茎秆极限切应力、单位面积切割功耗分别减小了6. 6%、3. 9%。
In order to reduce the cutting force and energy of millet stem, the reciprocating cutting test bench was developed to carry out the single factor cutting tests in different harvesting dates, stem region, combination of cutter, cutting inclination angle, blade oblique angle, average cutting speed and stem feeding speed. The response tests were carried out for three factors: average cutting speed, cutting inclination angle and blade oblique angle based on the single factor tests. The results of single factor tests showed that the cutting stress and unit area cutting energy were decreased with the increase of moisture content during harvest period. The cutting stress and unit area cutting energy were decreased with the increase of stem height, and the cutting stress and unit area cutting energy of internodes were lower than those of nodes. The cutting stress and unit area cutting energy of double-support cutting form were lower than those of single-support cutting form. When the cutting inclination angle was 0°~20°, the cutting stress and unit area cutting energy was firstly decreased and then increased with the increase of cutting inclination angle. When the blade oblique angle was 0°~48°, the cutting stress was decreased with the increase of blade oblique angle, but the unit area cutting energy was decreased firstly and then increased. When the average cutting speed was 0.5~1.5 m/s, the cutting stress and unit area cutting energy were decreased firstly and then changed steadily with the increase of average cutting speed. The stem feeding speed had no significant effect on the cutting mechanical properties of the millet stem. The results of the response test showed that the order of three factors affecting the cutting stress and unit area cutting energy were as follows: average cutting speed, blade oblique angle and cutting inclination angle. The optimal cutting parameters were the average cutting speed of 1.19 m/s, the cutting inclination angle of 7.2°and the blade oblique angle of 36.4°. Under the optimal p
作者
张燕青
崔清亮
郭玉明
李红波
ZHANG Yanqing;CUI Qingliang;GUO Yuming;LI Hongbo(College of Engineering, Shanxi Agricultural University, Taigu 030801, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第4期146-155,162,共11页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2016YFD0701801)
关键词
谷子茎秆
切割
力学特性
试验
millet stem
cutting
mechanical properties
experiment
