手持冲击梳刷式油茶果采摘装置设计与试验

Design and Experiment of Hand-held Impacting Comb-type Camellia oleifera Fruit Harvester

针对丘陵山地油茶果人工采摘效率低、大型机械采收难且花苞损伤大等问题,设计了一种手持冲击梳刷式油茶果采摘装置,通过冲击指的碰撞作用和指间梳刷作用采摘油茶果,可有效降低花苞损伤率。以采摘装置质量最小化为目标,利用Ansys Workbench拓扑优化模块进行轻量化设计,机架减轻近30.59%;建立“冲击指-油茶果”碰撞模型和“主枝-细枝-茶果”三摆动力学模型,明确影响油茶果采摘效果的主要因素为油茶果的质量和压入变形量、冲击指质量和转速、枝条长度和质量;进而以冲击指转速和指间夹角、装置梳刷次数为试验因素,以采摘速率、采净率和花苞损伤率为评价指标,开展油茶果采摘试验并采用响应面分析法处理试验数据。结果表明,冲击指转速对采摘效果的影响最为显著,且当冲击指转速为409.8 r/min、指间夹角为4.1°、装置梳刷4.5次时,装置的采摘性能最佳;此时,油茶果采摘速率为43.67 kg/h、采净率为86.42%,花苞损伤率低于8.89%,满足高油茶果采净率和低花苞损伤率的工作要求。

Camellia oleifera is a unique woody oil tree species in China,which plays an important role in grain and oil security.However,there are problems with harvesting of Camellia oleifera fruits in hilly and mountainous areas such as low efficiency in manual harvesting,difficulties in flower and fruit synchronization,and difficulties in large-scale mechanical,limiting the development of mechanized harvesting of Camellia oleifera fruits.A hand-held impacting comb-type Camellia oleifera fruit harvester was designed.The impact component of the device was provided with a buffer sleeve and an angle adjustment mechanism.The harvesting of Camellia oleifera fruit was completed by using the collision and brushing action of the impact finger with the Camellia oleifera fruit.The goal was to minimize the quality of harvester.The topology optimization section of Ansys Workbench 19.2 software was used to lightweight design the harvester.After optimization the weight reduction of the rack was nearly 30.59%.Meanwhile,the"impact finger-Camellia oleifera"collision model and"main branch-secondary twig-fruit"three pendulum dynamic model were established.By analyzing,it can be seen that the main factors affecting the abscission of Camellia oleifera fruit were the mass and pressing deformation of Camellia oleifera fruit,the quality and rotation speed of the impact finger,and the length and quality of the branches after collision.The rotational speed of the impact finger,the number of comb strokes,and the angle between the impact fingers were taken as experimental factors.The rate of harvesting efficiency and net harvesting rate of camellia fruits as well as the rate of flower bud abscission were calculated under different experimental conditions.The experiment results were analyzed by response surface analysis.The results indicated that the performance of the picking device was best when the number of combs was 4.5,the rotating speed of the impact finger was 409.8 r/min,and the impact finger included angle was 4.1°.In this case,the picking rate and net picking rate of Camellia oleifera fruit were 43.67 kg/h and 86.42%,and the falling rate of bud was 8.89%,which can meet the working requirements of high net picking rate and low damage rate of flower buds.