Design And Optimization Of Multi-functional Shovel-screen Type Self-balancing Digging Harvester

The harvesting task of China's typical agricultural materials,especially peanuts and residual plastic film,is so arduous that mechanized harvesting has become an inevitable trend of agricultural materials harvesting.Shovel-screen type peanut digging harvesters are widely used in segmented harvesting of peanuts,but there are problems such as large vibration and poor soil cleaning effect.Therefore,in order to control the target with small vibration and good soil cleaning effect,a shovel-screen type self-balancing peanut digging harvester was designed and optimized on the basis of experimental research.In addition,during investigations and experiments,it was found that after the harvest of peanuts,potatoes,corn and other crops,the residual agricultural film in the farmland was not effectively recovered,causing serious environmental pollution.At present,the domestic residual plastic film recycling devices are not only unsatisfactory for the recovery of severe broken film,but also have a single function,poor economic performance and low commercial value.Based on the similarities of process and working principle between peanut digging harvesting and residual plastic film recovery,a multi-functional shovel-screen type self-balancing digging harvester was designed by improvement and optimization of the screen-screen type self-balancing peanut digging harvester.Through convenient assembly and parameter adjustment of key components,it has realized a multi-purpose machine,which can not only harvest peanuts but also collect the residual plastic film.And then a field test was used to test the recovery effect of residual plastic film of the multifunctional machine.The main research contents are as follows:?1?Design and analysis of the screen-screen type self-balancing peanut digging harvester.The key components such as digging shovel,vibration driving device and vibrating screen were designed.The dip angle of the digging shovel was determined as 20^o.The anti-parallelogram mechanism was applied to achieve self-balanced of the dual-screen vibrating screen.The mass of the eccentric block used in the counterweight was determined as 1.786kg,and the eccentricity distance?the distance from eccentric block centroid to the vibration driving axle?was determined as 13.5mm.Besides,during peanut harvesting operations,the rod spacing of bar screen was determined as 12mm.The rationality of structural design was verified by modal analysis and vibration test.?2?Experimental study on the screen-screen type self-balancing peanut digging harvester.The forward velocity,vibration amplitude of bar screen,rotational speed of vibration driving axle were taken as the main influencing factors,and the total loss rate,soil containing rate and vibration acceleration were used as indexes in the experimental study.By single factor test and response surface comprehensive optimization test,the influencing rules of factors on each index and the significant levels were determined,and the multivariate quadratic polynomial regression model of factors on each performance index was established.The order of the main factors affecting the total loss rate was obtained:rotational speed of vibration driving axle>vibration amplitude of bar screen>forward velocity;the order of the main factors affecting the soil containing rate was obtained:rotational speed of vibration driving axle>forward velocity>vibration amplitude of bar screen;the order of the main factors affecting the vibration acceleration was obtained:rotational speed of vibration driving axle>vibration amplitude of bar screen>forward velocity.After comprehensive optimization,the optimal parameter combination was obtained,which was 1.0m·s^-1 as the forward velocity,48mm as the vibration amplitude of bar screen,240 rpm as the rotational speed of vibration driving axle,with this optimal parameter combination,the total loss rate was 1.73%,the soil containing rate was 7.32%,the vibration acceleration was 3.02 m·s^-2,each index was in line with the standard requirements.?3?Design of the multi-functional shovel-screen type self-balancing digging harvester and its verification test for residual plastic film recovery.On the basis of the shovel-screen type self-balancing peanut digging harvester,the multifunctional shovel-screen self-balancing digging harvester was designed,which can be used to harvest peanuts and collect residual plastic film.In view of the residual plastic film recovery function of multi-functional machinery,some key components,such as vibrating screen,multi-stage membrane soil separation device,film collecting and film unloading device,were designed.The vibration amplitude of the vibrating screen was determined to be 48 mm,the rotational speed of the vibration driving shaft was 222 rpm,and the inclination angle of back-screen was 10°.Through the field test of residual plastic film recovery,the three test indexes were obtained:residual film recovery rate was 85.72%,membrane-to-vehicle ratio was 0.5,and vibration acceleration was3.32m·s^-2,which showed that the overall performance of the machine was good during residual plastic film recycling.