振动和拨辊推送式藠头收获机研制

Development of a vibrating and roller pushing type Allium chinense harvester

针对现有根茎类作物收获机用于藠头收获时存在的果土分离不彻底、埋果率高、地形适应性差等问题,该研究研制了基于“杆筛式振动碎土+拨辊推送式多级分离”技术的自走式藠头收获机。对挖掘和果土分离过程中的物料状态和作业机理进行了分析,建立模型计算得到了挖掘装置的位置和深度、杆筛式振动装置的振幅和曲柄转速、拨辊的尺寸和位置等关键参数,基于可调式挖掘装置、杆筛式振动装置、拨辊推送式多级分离装置组成加工了藠头收获机样机。针对研究内容设计了田间挖掘试验和整机性能试验,对以上装置及整机的作业性能进行验证。田间试验表明:该机实际挖掘深度稳定,漏挖率、埋果率、总伤果率分别为0.31%、3.20%、5.87%,有效收获率为93.23%。整机结构及布局合理,性能稳定,能够满足当前丘陵山区条件下藠头机械化收获的需求。

Allium chinese is one type of the small underground bulb crops,mainly distributed among the hilly and mountainous areas in southern China.The growing place is normally characterized by the complex and changeable terrain with the high soil viscosity.Therefore,some difficulties can be posed as the mechanized harvesting of Allium chinense,such as the high requirements for separating fruit and soil,the great difficulty in separating,and terrain adaptability.In this study,a fruit soil separation technology was developed for the“rod and sieve type vibration separation+roller pushing type multistage separation”.A walking device with high chassis crawler was adopted to place the working parts,such as the adjustable digging device,the rod and sieve type vibration separation device,and the roller pushing types multistage separation device between the two crawlers.The size of the machine was reduced suitable for the small plot harvesting operation under complex terrain.The excellent working performance was achieved in the digging shovel in the middle of the crawler.The strong stability of excavation depth was promoted in the fruit-soil separation of the less excavation depth.The rod and sieve type vibration separation device was realized the first step of conveying and separation by vibrating and impacting the clods.There were different linear speeds at the root and end of the vibrating rod.Specifically,the large clods were used to turn over the clods,and then cause the clods to be longitudinally sheared and damaged.Excellent conditions were created for the subsequent separation of fruit and soil.The clod was crushed and fell back to the field,as the fruit holding space was changed to form the adjacent rollers during the operation of the Roller pushing type multistage separation device.The fixed soil pressure rod of soil crushing was used to squeeze the clods into the fruit holding space,in order to achieve the efficient crushing of the soil block for the better fruit and soil separation.As such,the large clods were avoided to transport on the surface of the roller group without entering the fruit holding space.Each device in the working process was analyzed using theoretical calculation and simulation.The key parameters were obtained,such as the position and depth of the adjustable digging device,the amplitude and crank speed of the rod and sieve type vibration device,as well as the size and position of the roller.The Allium chinense harvester was finally developed,including the adjustable digging,the rod and sieve type vibration,and the roller pushing type multistage separation device.The field excavation test were designed to verify the performance of each device and the complete machine.It was found that there was the stable actual digging depth of the machine,where the rate of missed digging was 0.31%,the rate of buried fruit was 3.20%,the total rate of damaged fruit was 5.87%,and the effective harvest rate was 93.23%.Therefore,the stable performance was achieved in the reasonable structure design and layout of the whole machine.The improved harvester can fully meet the demand for the mechanized harvesting of Allium chinense under the current hilly and mountainous conditions.