Studies On Key Components Of Digging-pulling Cassava Harvester

As the fifth economic crop in the world, cassava is extensively planted globally, especially in tropical and sub-tropical areas. Cassava is characterized with short time for harvest, big and intensive labour, unfavorable environment, and the sandy loam soil and clay soil would make harm to the cassava and the root and even can not get harvest. To mechanize the cassava could make the industry of cassava develop in a sustainable way.This paper adopts cassava harvester as research object, with the digging and clamp-transportation after current digging-pulling cassava harvester experience as its research problems. In addition, this paper studies the key element of digging shovel and clamp-transportation of the digging-pulling cassava harvester, establishes three-dimensional model of it with creative new technology, establishment and analysis of speed model and mechanics model as well as finite element. Research subject are as follows:(1)With the principle of increasing the ability of earth crumbling, earth leaking, decreasing the resistance of earth digging, decreasing the rate of cassava breaking and cutting as well as weight decrease, the paper designs a new form of digging-shovel which is suitable for digging cassava root, and the paper also studies ways of improving digging-shovel when digging into the earth. According to the principle of bionics, the paper designs the structure of digging-shovel, confirming the main structure parameters. The author also analyses the stress of digging-shovel and cassava, and calculates the total pulling resistance when digging-shovel is moving forward.(2)To establish transportation speed model of clamping-transportation structure when clamp single cassava stalk, analyse relation of speed and relation between every key sports parameter, the direction of pulling and number, establish speed model of two continuous cassava clamping and pulling, analyse the prerequisite of no collision and interaction. Analyse the relation of every key kinesiology parameters, acquire the prerequisite of parameter range of angle of clamping structure and clamping speed ratio, confirm the best parameter range of four key parameters.(3)With the principle of increasing the clamping force, satisfying the maximum requirement of clamping force, firmly clamping the cassava stalk, the paper studies and designs clamping-transportation structure, confirm the way of firm-clamping of cassava stalk, designs firm-clamping structure, and compare and analyse the former firm-clamping way. The paper also designs each component part of clamping-transportation structure, by analysis and culculation, and confirms the main structure and parameter.(4)According to the speed decomposition chart when pulling cassava root, the paper establishes mechanics model of clamping-tranportation structure of pulling and transporting the cassava root, and acquires the calculation of pulling force and clamping force. Additionally, the paper analyses the stress of the earth working on root, calculates the pulling-and-clamping force needed when clamping-transportaion structure pulling cassava roots out, and also acquires the clamping force needed by cassava stalk when clamping and transporting. The paper designs and calculates the spring according to the clamping force of pulling cassava root.(5)The paper elaborates the stress of finite element of digging shovel by ABAQUS software, as well as designs the three-dimensional model by SolidWorks software of digging-pulling cassava harvester.(6)The paper conducts experiment and analyses the cassava harvester on the farm in digging and clamping-transportation, optimizing the parameter of each parts. According to the result of cassava harvester, we make experiment on cassava digging ratio, cassava breaking ratio, cassava pulling ratio and machine producing rario, and we analyze the result of the experiment, which indicates the fact that the cassava harvester could finish the digging-pulling work and run better.