摘要
针对目前国内山核桃破壳机实用机型少,破壳率较低,果仁损伤率较高等情况,提出了一种仿生敲击(即模仿人工加工山核桃的方式)破壳方式,研制一款仿生敲击式山核桃破壳机。根据山核桃的物料特性以及破壳时所需的各项力学特性参数,建立了破壳机构设计的数学模型。确定了敲击臂的结构尺寸,优化了凸轮结构,并最终得到了凸轮的实际轮廓曲线。该文阐述了破壳机的总体结构与性能,建立了整机的三维实体模型,并根据建模制造了样机。该样机通过现场试验,结果表明:山核桃的含水率为14.55%~16.35%,大小为直径18~22 mm(沿缝合线方向)时,破壳率为99.41%,果仁损伤率为6.25%,生产率为94.93 kg/h,满足生产要求。该研究丰富与完善了坚果类果实的破壳机理与方法,为含隔坚果类的破壳机具设计与开发提供系统的理论依据和应用基础。
At present, extruding crack and centrifugal shell-breaking methods are adopted as the main strategies for pecanshell-breaking equipment. But the low production rate is hard to be improved. Meanwhile, the bad processing quality willaffect the further processing, which restricts the development of the pecan processing industry. To solve such problems, thisstudy proposed a bionic knock method, which imitated the artificial processing to shell pecan, and developed a bionic knocktype shell breaker. Design and experiments were both mainly focused on the structure and parameters of the shell breaker. Thepaper described the overall structure of prototype and introduced the technical parameters of shell breaker, and thethree-dimensional model was built by Pro/Engineer software. In this study, cell feed wheel was designed to translate pecan intofeed pipe from hopper one by one like water flow, and thus the method could avoid pecans plugging the feed pipe. The bottomof the pipe was linked with shelling system, which was one of the most important parts during the study. In order to figure outa more efficient shelling method, a bionic knock structure was designed based on the particle properties and mechanicalbehavior of pecan rupturing under knock loading, and the mathematical model of designing the shelling system was built. Thesystem included 3 parts： disk-cam, support point and mechanical arm. The mechanical arm could roll around the support pointin a certain angle range, and through the profile curve of disk-cam, the movement of mechanical arm could be controlled tofinish shelling process. The groove structure was designed, which could reduce the deformation of pecan under the knock toprotect the kernel from damage, and within a few sockets on the inner wall of groove, it could change the surface load intolinear load and achieve a better shell-breaking quality. According to the movement requirements of shelling system, thestructure dimension of mechanical parts was built, the push movement angle of the cam was optimized by the inverse methodand the practical cam profile curve was designed. What was more, the transmission system and the time sequence relationshipon all the actions were both introduced, and the transmission system diagram and the one time sequence diagram on shellbreaker were showed in the paper. After the physical prototype of mechanism was manufactured, the field test was performed,and 3 groups of pecans were selected. The results showed that the prototype working performance was stable and high-quality.While the rotating speed of camshaft was 52 r/min, the pecan moisture content was set nearly to 14.55%-16.35%, and thediameter volume was from 18 to 22 mm, the shell-breaking rates of the 3 test groups were 99.59%, 99.40% and 99.31%respectively, which were high, and the kernel damage rates were 5.77%, 7.00% and 6.01% respectively, which were low. Theprocessing efficiency was also higher than the traditional shelling equipment, which could reach 95.54, 98.00 and 91.25 kg/hrespectively for the 3 groups of pecans. The test performance of prototype could basically meet the production demands. Theresearch can enrich and perfect the mechanism and method for shell-breaking of walnut, and provide the technology andequipment support to realize the mechanization of pecan processing industry.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第3期257-264,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然资金面上项目(51475002)
关键词
农业机械
模型
试验
山核桃
破壳机
仿生敲击
破壳率
果仁损伤率
agricultural machinery
models
experiments
pecan
shell breaker
bionic-impact
break shell rate
kernel damaged rate
作者简介
丁冉，男，安徽人，从事机械设计及其自动化研究。合肥安徽农业大学工学院，230036，Email：dr910621@126．com
通信作者：曹成茂，男，汉族，安徽六安人，教授，博士生导师。主要研究方向：农业机械化工程，智能检测与控制技术。合肥安徽农业大学工学院，230036，Emaihcaochengmao@sina．com中国农业工程学会会员：曹成茂（会员号：E041300001M）
