Analysis And Test Of Vibration Parameters Of Vibrating Jujube Harvesting Machine

Jujube has a long history of cultivation in China.Jujube trees are drought and flood resistant and are suitable for Xinjiang,where there is little rain and long sunshine hours.Since the economic value of jujube was developed,the cultivation area of jujube in Xinjiang has increased significantly with the strong support of the state.However,until now jujube harvesting still relies on manual labor,and the high cost of hiring labor leads to high cost of jujube harvesting,and the harvesting link becomes an important factor limiting the development of jujube industry.Based on the current situation of jujube harvesting in Xinjiang region,this study conducted jujube vibration harvesting experiments to obtain the best vibration parameters of eccentric vibration type jujube harvesting machine and to provide theoretical basis for advancing the development of vibration type jujube harvesting machine,and the main findings are as follows:(1)The literature analysis method was used to understand the current research status of vibratory forest fruit harvesting machines at home and abroad and the research methods of vibratory harvesting commonly used at present.Through reading the literature,it is known that vibration frequency,vibration position,vibration amplitude and vibration time are the four factors that directly determine the harvesting efficiency.(2)Through the survey and research method,learned that the actual planting pattern of date palm orchards around Alar City of the First Division of Xinjiang Production and Construction Corps is dwarf dense planting,measured the basic parameters of date palm trees such as tree height,crown diameter,tree trunk height and tree trunk diameter,and analyzed the measured data to get that the tree height is tree heights between 1.5～3.5 m,trunk diameters mostly between80～90 mm,crown diameters between 2000～3000 mm,and trunk heights mostly between 300～400mm.The measured values provide the basis for the subsequent establishment of the date palm model.We also investigated the harvesting methods of jujube around Alar City,the First Division of Xinjiang Production and Construction Corps,and analyzed the advantages and disadvantages of jujube harvesting methods to provide a reference for the determination of the research content.(3)Measured the weight,water content,natural fruit drop rate and connection force between jujube fruits and jujube branches during the harvesting period,and obtained the average weight of jujube fruits during the harvesting period as 6.58 g,the average water content as 26.18%,the natural fruit drop rate as 37.20%,and the average connection force of jujube fruits in mid-November as 0.524 N.By measuring these four values,understood the real situation of jujube fruits during the harvesting period.and to provide a reference for the analysis of jujube fruit drop conditions.(4)Based on the results of the study,a date palm tree with dimensional parameters ranging from1.5 to 3.5 m in height,80 to 90 mm in trunk diameter,2000 to 3000 mm in crown diameter,and300 to 400 mm in main trunk height was selected and a three-dimensional model of the date palm tree was established using Solid Works 3D software to analyze the intrinsic frequency of the date palm tree and simulate the vibration harvesting process of the date palm.Analyzed to obtain the best vibration frequency of 15.963 Hz.The stress response gradually increased with the increase of eccentric block weight.The vibration process was simulated by changing the weight of the eccentric block,and the stress response was obtained to increase gradually with the increase of the weight of the eccentric block.The analysis of the jujube falling conditions and the design of pre-tests were carried out to select the range of values for the four factors affecting the vibration effect,and the final range was 10～22Hz vibration frequency,500～700g eccentric block mass,100～300mm clamping height and 3～11s vibration time.(5)The actual harvesting was carried out by single-factor variation test and four-factor five-level test,and the results were analyzed by taking the harvesting rate as the only criterion,and the four factors were finally obtained in the order of clamping height,vibration frequency,eccentric block quality and harvesting time,and the reasons for the difference between the actual optimal vibration frequency and the optimal frequency obtained from simulation were analyzed,and the optimal parameters were finally determined as vibration frequency,19 Hz,eccentric block weight,650 g,clamping height,300 mm and harvesting time,9 s.The combination of the best vibration parameters was tested,and the average harvesting rate could reach more than 90%,which could achieve the purpose of vibration harvesting of red dates.