曹成茂,蒋兰,吴崇友,李正,汪天宇,丁冉.山核桃破壳机加载锤头设计与试验[J].农业机械学报,2017,48(10):307-315.
CAO Chengmao,JIANG Lan,WU Chongyou,LI Zheng,WANG Tianyu,DING Ran.Design and Test on Hammerhead of Pecan Shell-breaking Machine[J].Transactions of the Chinese Society for Agricultural Machinery,2017,48(10):307-315.
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山核桃破壳机加载锤头设计与试验   [下载全文]
Design and Test on Hammerhead of Pecan Shell-breaking Machine   [Download Pdf][in English]
投稿时间:2017-06-22  
DOI:10.6041/j.issn.1000-1298.2017.10.039
中文关键词:  山核桃  破壳  加载锤头  窝眼凹槽式  裂纹引导
基金项目:国家自然科学基金项目(51475002)
作者单位
曹成茂 安徽农业大学 
蒋兰 安徽农业大学 
吴崇友 农业部南京农业机械化研究所 
李正 安徽农业大学 
汪天宇 安徽农业大学 
丁冉 安徽农业大学 
中文摘要:针对现有的山核桃破壳机多采用点、线等单一的加载接触形式进行破壳,使得工作过程中山核桃受力大小分布不均,从而导致低破壳率、高果仁损伤率的现象,设计了多种不同加载接触形式的锤头类型,以山核桃破壳后破壳率、果仁损伤率、露仁率、裂纹分布为评价指标,通过试验探究了不同加载接触形式下的破壳效果。通过有限元分析探究了不同窝眼个数的锤头对破壳过程中裂纹分布和扩展的影响,并以锤头结构参数和加载方向为试验因素进行了正交试验,确定了最佳锤头结构参数组合。试验结果表明,凹槽式锤头结构能够降低加载方向因素对破壳效果影响的显著性;凹槽中附加的窝眼能够使破壳后的果壳产生大量局部裂纹点,并沿窝眼棱线扩展产生裂纹,具有裂纹引导作用;窝眼个数增加,山核桃破壳后的裂纹数增加且裂纹分布均匀、范围广,有效提高了山核桃的破壳质量;当凹槽直径为28mm,窝眼个数为7时,破壳效果最理想,破壳率、一露仁率、二露仁率、果仁损伤率的均值分别为98.88%、37.05%、57.24%、5.71%。
CAO Chengmao  JIANG Lan  WU Chongyou  LI Zheng  WANG Tianyu  DING Ran
Anhui Agricultural University,Anhui Agricultural University,Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture,Anhui Agricultural University,Anhui Agricultural University and Anhui Agricultural University
Key Words:pecan  shell-breaking  loading hammerhead  groove shape with sockets  crack guide
Abstract:At present, it is universally acknowledged that the mechanical shell-breaking method is regarded as the main research strategies in the process of pecan shell-breaking equipment design. The design and improvement of shell-breaking method and principle had been studied extensively. However, in each kind of shell-breaking method, the research on the loading contact form between the broken shell mechanism and the pecan was neglected. Whether in the study of pecan shell-breaking principle and method or the design of mechanical equipment, the load which was provided with a single contact form was bore for pecan, such as point load or line load. In the course of processing, the size of the shell-breaking force was prone to cause the partial breakage of the shell or the serious damage of the nut, which led to the phenomenon of low shell-breaking rate and high nut damage rate. Therefore, the groove shape hammerhead with sockets was developed. The hammerhead structures of different loading contact form were designed. And the shell-breaking effect on different loading contact form was researched by test. When the pecan was broken, the shell-breaking rate, nut damage rate and exposure nut rate of pecan were deemed as evaluation index. The crack distributions which were formed of three hammerheads in different loading directions were compared and analyzed. The finite element analysis software Abaqus was used to research the distribution and propagation of crack in the process of the shell-breaking, which considered the structure of the hammerhead with four different numbers of sockets as the variable. The orthogonal test which considered the structure parameters of the hammerhead and the loading direction as experimental factors was designed and used to determine the optimum combination. The results showed that the structure of the hammerhead in the groove shape can reduce the influence of the loading direction factor on the shell-breaking effect. Containing a plurality of sockets can make the pecan shell generate a large number of local crack points which extended along the tangent line of the socket to produce and extend crack. This structure can act as a crack guide. With the increase of number of sockets, the crack distribution of the pecan shell was uniform and the range was wide. This structure can improve the quality of shell-breaking. When the groove diameter was 28mm, the number of sockets was 7, the most satisfactory shell-breaking effects were obtained, which generated the shell-breaking rate of 98.88%, the first grade nut rate of 37.05%, the second grade nut rate of 57.24%, and the nut damage rate of 5.71%.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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