农业工程学报
農業工程學報
농업공정학보
Transactions of the Chinese Society of Agricultural Engineering
2015年
21期
9-16
,共8页
贾洪雷%郭慧%郭明卓%王立春%赵佳乐%范旭辉
賈洪雷%郭慧%郭明卓%王立春%趙佳樂%範旭輝
가홍뢰%곽혜%곽명탁%왕립춘%조가악%범욱휘
农业机械%模型%试验%弹性镇压轮%理论模型%覆土%仿真
農業機械%模型%試驗%彈性鎮壓輪%理論模型%覆土%倣真
농업궤계%모형%시험%탄성진압륜%이론모형%복토%방진
agricultural machinery%models%experiment%elastic press wheel%theoretical model%soil-covering%simulation
为提高播种机的播种及镇压性能，解决播种作业中覆土后即时镇压的难题，结合橡胶类材料的变形理论与轮胎力学的研究基础，建立基于种沟沟型的理论模型，并设计出一种具有覆土功能的弹性镇压轮，镇压轮横截面由顶端连通的两个腔室组成，通过镇压轮侧缘与种沟接触产生的挤压力以同时实现覆土和镇压作业。利用ABAQUS软件对镇压轮进行有限元仿真分析，考察其覆土及镇压性能，通过有限元仿真分析证实该模型可行有效。通过与双圆盘覆土器和传统橡胶镇压轮的田间对比试验测得，该文所设计的弹性可覆土镇压轮作业后种子平均覆土深度为34 mm，变异系数为15.68%，镇压后种子上方距离地表5 cm的土壤紧实度为33.5 kPa，变异系数为13.97%，应用双圆盘覆土器和传统橡胶镇压轮作业后种子平均覆土深度为35.3 mm，变异系数为17.51%，镇压后种子上方距离地表5 cm的土壤紧实度为26.5 kPa，变异系数为15.32%，田间对比试验证实弹性可覆土镇压轮和双圆盘覆土器均可满足玉米播种作业对覆土深度的要求，但弹性可覆土镇压轮对土壤的镇压强度大于传统橡胶镇压轮，同时由覆土深度变异系数和镇压强度变异系数可以看出，弹性可覆土镇压轮在作业过程中的覆土深度稳定性和镇压强度稳定性均优于双圆盘覆土器和传统橡胶镇压轮。
為提高播種機的播種及鎮壓性能，解決播種作業中覆土後即時鎮壓的難題，結閤橡膠類材料的變形理論與輪胎力學的研究基礎，建立基于種溝溝型的理論模型，併設計齣一種具有覆土功能的彈性鎮壓輪，鎮壓輪橫截麵由頂耑連通的兩箇腔室組成，通過鎮壓輪側緣與種溝接觸產生的擠壓力以同時實現覆土和鎮壓作業。利用ABAQUS軟件對鎮壓輪進行有限元倣真分析，攷察其覆土及鎮壓性能，通過有限元倣真分析證實該模型可行有效。通過與雙圓盤覆土器和傳統橡膠鎮壓輪的田間對比試驗測得，該文所設計的彈性可覆土鎮壓輪作業後種子平均覆土深度為34 mm，變異繫數為15.68%，鎮壓後種子上方距離地錶5 cm的土壤緊實度為33.5 kPa，變異繫數為13.97%，應用雙圓盤覆土器和傳統橡膠鎮壓輪作業後種子平均覆土深度為35.3 mm，變異繫數為17.51%，鎮壓後種子上方距離地錶5 cm的土壤緊實度為26.5 kPa，變異繫數為15.32%，田間對比試驗證實彈性可覆土鎮壓輪和雙圓盤覆土器均可滿足玉米播種作業對覆土深度的要求，但彈性可覆土鎮壓輪對土壤的鎮壓彊度大于傳統橡膠鎮壓輪，同時由覆土深度變異繫數和鎮壓彊度變異繫數可以看齣，彈性可覆土鎮壓輪在作業過程中的覆土深度穩定性和鎮壓彊度穩定性均優于雙圓盤覆土器和傳統橡膠鎮壓輪。
위제고파충궤적파충급진압성능，해결파충작업중복토후즉시진압적난제，결합상효류재료적변형이론여륜태역학적연구기출，건립기우충구구형적이론모형，병설계출일충구유복토공능적탄성진압륜，진압륜횡절면유정단련통적량개강실조성，통과진압륜측연여충구접촉산생적제압력이동시실현복토화진압작업。이용ABAQUS연건대진압륜진행유한원방진분석，고찰기복토급진압성능，통과유한원방진분석증실해모형가행유효。통과여쌍원반복토기화전통상효진압륜적전간대비시험측득，해문소설계적탄성가복토진압륜작업후충자평균복토심도위34 mm，변이계수위15.68%，진압후충자상방거리지표5 cm적토양긴실도위33.5 kPa，변이계수위13.97%，응용쌍원반복토기화전통상효진압륜작업후충자평균복토심도위35.3 mm，변이계수위17.51%，진압후충자상방거리지표5 cm적토양긴실도위26.5 kPa，변이계수위15.32%，전간대비시험증실탄성가복토진압륜화쌍원반복토기균가만족옥미파충작업대복토심도적요구，단탄성가복토진압륜대토양적진압강도대우전통상효진압륜，동시유복토심도변이계수화진압강도변이계수가이간출，탄성가복토진압륜재작업과정중적복토심도은정성화진압강도은정성균우우쌍원반복토기화전통상효진압륜。
The soil coverer and the press wheel are the main parts of the corn planter, and their performances are directly related to the growth and the output of the corn. The operation of soil compaction immediately after the soil covering can improve the soil moisture content and reduce soil evaporation. The application of elastic material in the press device also has a positive effect on solving the phenomenon of soil adhesion during the operation of seeding. In order to improve the performances of seeding and soil compaction of the corn planter under conservation tillage, an elastic press wheel with the function of covering soil was designed through the combination of the deformation theory of rubber material and the tire mechanics to solve soil covering and soil compaction simultaneously after corn planting. The force of contact unit during the operation process of press wheel was analyzed, a theoretical model of the press wheel was built up based on shape characteristics of furrows, and an elastic press wheel with a double-cavity structure was presented. Depending on the extrusion force caused by the contact between the lateral edge of press wheel and furrows realize the functions of soil covering and soil compaction simultaneously. The structural parameters of the elastic press wheel with the material of styrene butadiene rubber (SBR) was determined through the analysis of the theoretical mode as follows: the diameter, the width and the thickness of the press wheel were 500, 180 and 8 mm, respectively; the width of cross section of single-cavity of the press wheel was 70 mm, the cross section of single-cavity of the press wheel was composed with the curvature radius of the lateral edge of the press wheel respectivelyρ1,ρ2 andρ3, which were 30, 135 and 60 mm separately; the internal pressure of the press wheel was 500 Pa, and the external load during working was 475 N. The theoretical model was confirmed by the finite element simulation based on ABAQUS through analyzing the stress, strain and displacement of soil, contact area and vertical contact force. The simulation results showed that the elastic press wheel could realize these objectives of soil covering and soil compaction with less disturbance of the soil and better working stability. A field experiment was conducted to validate the theoretical model and the elastic press wheel’s functions of soil covering and soil compaction, and the results showed that the soil covering depth of seed after compacting operation was 34 mm, the coefficient of variation of the seed’s soil covering depth after compacting operation was 15.68%, the soil compactness was 33.54 KPa in the top 50 mm soil layer of the seed furrow, and the coefficient of variation was 13.97%, which indicated that the elastic press wheel would work effectively in the functions of soil covering and soil compaction. An additional comparative experiment was carried out between the elastic press wheel presented in the paper and the double-disc coverer and rubber press wheel widely used in precision planter, and the desired soil covering depth of seed was both obtained in the corn planting, but the corn planter equipped with elastic press wheel worked more effectively in the functions of soil compaction, and our result indicated that the corn planter equipped with elastic press wheel could also result in good performances on the stability of soil covering and soil compaction. Therefore, this method and the theoretical model are demonstrated to be practical and feasible, and the elastic press wheel presented in the paper can achieve the expected target of the soil covering and soil compaction with good performance of working stability.
