摘要
柔性脱粒能减少刚性脱粒冲击所带来的水稻籽粒破损,对柔性脱粒的研究与应用早已引起了农机研究者的广泛关注。为了比较柔性齿滚筒与刚性齿滚筒脱粒水稻的功耗差异,该文将脱粒滚筒视为刚体,脱粒齿视为弹性体,脱粒过程视为柔性脱粒齿对水稻籽粒的碰撞冲击过程,通过分析比较刚性齿与柔性齿脱粒过程中冲量矩及对水稻籽粒打击力,建立了刚性齿脱粒滚筒与柔性齿脱粒滚筒的功耗模型,同时通过对刚性和柔性脱粒过程碰撞冲量和动能损失的分析比较,从理论上证明了柔性齿脱粒相对于刚性齿脱粒具有动能损失小、功耗低。试验结果表明在喂入量相同情况下,脱粒齿直径相同的刚性齿滚筒比柔性齿滚筒的转矩大,消耗的功率也大,验证了柔性脱粒能降低打击力与功耗的理论分析结果。
The study and use of flexible threshing teeth are of interest to researchers in agricultural mechanization because flexible teeth appear to damage grain less than rigid teeth. For a flexible threshing tooth, consisting of an elastic beam fixed on one end, a differential equation of its deformation curve was created, the deformation of which was calculated by numerical methods, which provided necessary condition for dynamic analysis. The corresponding formulation of calculating power consumption was deduced based on theoretic analysis in this paper. The hypothesis was as follows： the threshing roller was regarded as rigid body, the threshing teeth as elastic bodies, and threshing as the impact between threshing teeth and paddy rice. The differences in impulse moment and beating force for paddy grain between the rigid threshing tooth and the flexible one were analyzed and compared, and their respective power-consumption models were established in this paper. By analyzing the loss of kinetic energy and impact momentum for the threshing processing using the rigid threshing tooth and the flexible one, we concluded that the loss of kinetic energy of flexible threshing was less than that of rigid threshing; likewise, power consumption by flexible-tooth threshing is less than that by rigid-tooth threshing if the feed rates and the rotary speed are equal.Meanwhile, the theoretical analysis results show that the beating force of the flexible tooth was less than that of the rigid tooth, which was confirmed experimentally. Experimental data showed that the threshing roller has to have a sufficiently high moment of inertia, and the engine enough power, to preserve the stability of the threshing process. We fabricated a number of experimental devices including a transducer for measuring torque, an apparatus to measure angular velocity, and a feeding test-bed. Experiments were conducted by measuring torsion and angular velocity, enabling us to compute the brake power of flexible-tooth and rigid-tooth threshing, respectively. There is an optimal value of tooth length that minimizes power consumption but that is unique for each kind of tooth.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2013年第5期12-18,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然基金项目资助(编号:51175173)
关键词
农业机械
试验
模型
柔性齿
刚性齿
脱粒功耗
脱粒水稻
agricultural machine
experiments
models
flexible tooth
rigid tooth
power consumption, paddythreshing
作者简介
任述光（1970-），男，湖南岳阳人，副教授，博士。湖南长沙市美蓉区农大路1号，湖南农业大学工学院，410128。Email：shgren2005@yahoo．com．cn
通讯作者：谢方平（1970-），男，湖南沅江人，教授，博士，中国农业工程学会会员（E041200208S），主要从事水稻机械化生产装备研究。湖南长沙市芙蓉区农大路l号，湖南农业大学工学院，410128。Email：hunanxie2002：@163．com
