【作者】 张伟；

【导师】 贺俊林；

【作者基本信息】 山西农业大学 ， 农业机械化工程， 2018， 硕士

【摘要】 钙果作为新型水果,随着市场的推广与认知,其种植面积在逐年增长,势头迅猛。采收是钙果生产加工环节中重要部分。由于人工采收效率较低,严重制约了钙果产业链的发展。近年来相关研究团队致力于钙果机械化收获的研究,已经存在双对辊式机械脱果装置。此装置提高了钙果收获效率。随着钙果种植规模的不断提升,产业要求更高效的采收方式,因此我们提出了田间采收的命题。钙果的田间采收,首先要解决的是挂果期枝条严重倒伏的问题。挂果枝条在成熟期倒伏贴近于地面;同时脱果方式要实现批量脱果。梳刷式脱果方案可以解决以上问题。本文钙果采收方案的动力来源选为装载机。钙果田间采收的机械设计方案的实现过程如下。首先在PRO/E中建立样机的三维模型,在ADAMS中,对采收流程进行了完整的动力学仿真。依据动力学仿真结果数据,在Ansys有限元分析平台上对虚拟样机的各关键部件进行了静力学仿真。静力学仿真以时间子步形式进行。将动力学仿真结果数据作为静力学有限元分析参数,寻找采收装置在工作流程中产生的薄弱环节,并予以加强、修正。通过优化机体,将机架体积减小近50%,质量减小近40%。装置载体为装载机。运动部件的动力来源于装载机的液压系统。主要液压部件有液压马达和双行程液压油缸。由于两部件工作交替进行,本方案采用两部件共用一条液压油路。由双向三通电磁阀控制两部件的供油。如此降低装载机械原车的改动。液压系统的控制,实时监控液压元件内的油压,配合运动部件的行程记录,以达到精准控制。运动部件的运动与链条连接,精确计算链条节距、节数、链轮参数以及两链轮轴间距。为验证装置解决枝条倒伏和采收能力,本文设计分析了梳刷采摘方式的样机试验。试验测试植株和成熟期果实外形特征,确定梳刷部件参数,梳齿间隙设定为10 mm可以同时实现枝条喂入以及果实分离。在动力学仿真软件中找出合理的采收机构运动方式。使用有限元仿真软件,对工况载荷下的各部件进行结构校核。其中,梳刷部件为关键部件,最大弯曲应力发生在梳齿根部,其值为51.634 MPa,结构可以满足采摘要求。制作梳刷部件运动机构样机,进行田间试验。采收率平均为80.6%,果实损伤率低于1%。在改进梳刷部件运动轨迹前提下,梳刷采摘方式可以满足田间机械化采收要求。更多还原

【Abstract】 As a new type of fruit Cerassus humilis,with the promotion and awareness of market,its planting area increased year by year,the momentum of rapid.Recovery is an important part of the production and processing of Cerassus humilis.The efficiency of artificial recovery is low,which seriously restrict the development of Cerassus humilis industry chain.Mechanical harvesting research team in recent years is committed to the fruit.Double roll type mechanical threshing device already exists,enhances the fruit harvesting efficiency.With the continuous improvement of fruit yield,it put forward the proposition of more efficient harvesting methods.Is the first to solve serious lodging branches during the fruiting period.The fruiting branches of this period lodge closing to the ground.The way of picking the fruit should meet the batch picking,and the comb brush scheme can solve the above problems.The fruit harvesting is a mechanical design scheme of Loader Based on.We us PRO/E to build a three-dimensional model.Complete dynamic simulation of the operation process with ADAMS.On the Ansys finite element analysis platform,the static simulation of the key parts of the virtual prototype is carried out.The dynamic simulation results are taken as the static finite element analysis parameters in the form of time substep.And then we find out the weak link in the working process of the collecting device,and to strengthen and correct it.In view of the light weight problem of the fuselage,the work intensity should be met first.The working strength should take into account the dynamic peak stress problem of mechanical work.Under the premise of meeting the working process and increasing the production range,the second generation model reduces the volume of the frame by nearly 50%and the mass decrease by nearly 40%.The control of the hydraulic system should monitor the oil pressure in the hydraulic components in real time,and coordinate the travel records of the moving parts to achieve accurate control.When the movement of the moving parts is connected with the chain,the chain is not the first option if the travel precision is required.In the case of using the chain,the chain pitch,the number of joints,the parameters of the sprocket and the distance between the two chain axle should be accurately calculated.In the mature period of Cerassus humilis,the fruiting branches lodging rate reaches more than 80%,leading to the mechanized harvesting difficulties.To solve the problem of the lodging branches,a new method of the fruit harvesting is put forward,which mainly includes the comb brush part and the motion mechanism.The comb brush part lodging lean close to the ground,lifting the lodging branches,and feed them into comb the clearance of the comb.The width of the tooth gap is between the diameter of the fruit and the diameter of the branch.The fruit rises with the part and is separated from the branches at the same time.In this study,the mechanical mechanism needed for harvesting process is designed,and the dynamics simulation and finite element analysis of the mechanism are carried out to check the strength of the mechanism.The test shows that the interstitial clearance is set to 10 mm,which could satisfy the branch feeding and the separation of the fruit at the same time.The picking rate of the comb brush parts is over 95%,the breakage rate less than 1%.It also can be found that the picking rate of the collecting device is related to the track of the brush part.更多还原