摘要
针对玉米穗茎兼收割台的需求,设计了一种横置滚筒式茎秆切碎装置,并对其切碎性能及割台摘穗性能进行了试验研究。通过对切碎装置工作原理的分析,确定在拉茎速度与切碎滚筒转速比值一定的条件下,以机器作业速度、动刀切割前角、切碎滚筒转速为自变量,以玉米果穗损失率、籽粒破碎率、籽粒损失率、茎秆平均切段长度和几何标准差为试验指标,利用Box-Benhnken Design中心组合试验设计原理,进行了3因素3水平正交旋转组合田间试验,利用Design-Expert软件对试验结果进行了响应面分析和回归分析,得到试验指标与试验因素间的数学模型。试验结果表明:机器作业速度和切碎滚筒转速与5个试验指标有二次非线性关系,动刀切割前角仅与茎秆平均切段长度、几何标准差有二次非线性关系,因素的交互项中仅机器作业速度与切碎滚筒转速的交互项对籽粒破碎率、茎秆平均切段长度有显著影响。对切碎滚筒转速进行圆整,得到最优参数组合为:机器作业速度为1. 35 m/s,动刀切割前角为52°,切碎滚筒转速为1 350 r/min,此时果穗损失率为1. 1%,籽粒破碎率为0. 23%、籽粒损失率为0. 74%、茎秆平均切段长度为30. 73 mm、几何标准差为1. 28。与田间试验结果对比可知,回归模型有很好的可靠性。将最优组合试验结果与优化前的参数组合(机器作业速度为1. 11 m/s,动刀切割前角为53°,切碎滚筒转速为1 657 r/min)得到的结果进行比较可知:优化后较优化前果穗损失率降低0. 4%,籽粒破碎率降低0. 784%,籽粒损失率降低1. 318%,茎秆平均切段长度缩短12. 20 mm,几何标准差减少0. 34。优化后试验指标低于标准规定的指标值,满足设计要求。
As a corn harvester for reaping both corn stalk and spike needs high efficiency and performance to harvest corn cob and corn stalk,a stalk chopper(SC) in horizontal roller type was designed. Aiming at studying the effect of parameters of chopper on picking and smashing performance,the working principle of SC was analyzed. Box-Benhnken Design(BBD) response surface method was used to design the field experience. An orthogonal rotary combination experiment was conducted with the working speed of corn harvester,the fixed angle of cutting knives and rotating speed of SC as three independent factors,as well as broken rate and loss rate of corn kernels,average length and geometric standard deviation of smashed corn stalk as four dependent indices,while using corn named Zhengdan as the test materials. Corn cobs,kernels and stalks were collected manually and calculated to get the results after every experiment. Design-Expert software was employed to analyze the test data,and mathematical equations between independent and dependent factors were gained. The results indicated that theindependent factors had a second nonlinear relationship with dependent indices,while only working speed of corn harvester and rotating speed of SC had significant effects on loss rate of corn kernels. Three factors all had significant effects on other dependent indices. The interaction between working speed of corn harvester and rotating speed of SC had a significant effect on broken rate of corn kernels and average length of corn stalk. Parameters optimization showed that when working speed of corn harvester was1. 35 m/s,the fixed angle of cutting knives was 52°,rotating speed of SC was 1 350 r/min,the device had optimal performance with loss rate of corn ear of 1. 1%,broken rate of corn kernels of 0. 23%,loss rate of corn kernels of 0. 74%,average length of broken stem of 30. 73 mm,and geometric deviation of1. 28. Compared with field test results,it was showed that the regression equation had a good prediction.In contract to the test with working speed of 1. 11 m/s,fixed angle of 53°,rotating speed of 1 657 r/min,the results showed that under optimal conditions loss rate of corn ear,broken rate of corn kernels,loss rate of corn kernels,average length of broken stem and geometric deviation were reduced by 0. 4%,0. 784%,1. 318%,12. 20 mm and 0. 34,respectively. The research result provided a basis for the stalk chopper of corn harvester for reaping both corn stalk and spike.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2018年第S1期266-274,共9页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2016YFD0701904)
关键词
玉米收获机
穗茎兼收
切碎装置
参数优化
田间试验
corn harvester
reaping stalk and spike
chopping device
parameter optimization
field test
