Design And Experimental Study Of Key Components Of A Small Self-propelled White Radish Harveste

As an important vegetable crop in China,white radish has many planting areas and a wide planting area.It has the characteristics of high quality and low price,and is deeply loved by the public,and has important economic value.However,the research on the mechanization operation equipment from sowing to harvesting of white radish in China started late,especially the harvesting equipment of white radish,is still in the blank stage.The traditional manual operation mode not only requires large labor force,but also has low harvest efficiency and high economic cost.It is not suitable for large-area planting mode,which hinders the development of the white radish market.This paper starts with the geometric and physical characteristics of radish.Through the preliminary investigation,combining the agronomic planting mode with the design of the white radish harvester,the overall design scheme of the small self-walking white radish harvester suitable for guizhou hills and mountainous areas was put forward.The structure and parameters of the unwinding and pulling clamping parts of the harvester are determined.The parameters of Guizhou clay were calibrated based on discrete element simulation,and then the simulation test of soil loosening mechanism was carried out.Finally,the factors affecting the resistance of the shovel are studied by bench test.The main research contents of this paper are as follows:(1)The geometric and physical characteristics of white radish were measured and the mechanical characteristics of mechanical harvesting were experimentally studied,which provided theoretical basis for the design and development of small self-walking white radish harvester.The geometric and physical parameters of white radish widely cultivated in Guizhou province were measured.The effects of stem diameter,stem moisture content and loading speed on stem tensile force of radish were studied.Green radish root was conducted by geometric parameters,soil moisture content for the size of the bai luobo detaching force needed for experimental study,the white radish root of geometric parameters and the extraction force proportional relationship,as the soil moisture content increases,bai luobo detaching force needed for the first reduce and then gradually increases,when the moisture content of 19.26% extraction force required minimum;By detaching bai luobo under natural state and after digging detaching bai luobo,found in the natural state of detaching green radish stem prone to stem fracture,to reduce the extraction force,the white radish root on both sides of the vehicle operations,the distance and depth of the digging dirt between the optimal combination,meet the demand of bai luobo harvest machinery design.(2)Based on the physical and mechanical parameters of radish measured in the early stage and the actual situation of planting agronomy and mountain operation,the overall goal and the scheme of key components of small self-walking radish harvester are proposed.By investigating the agronomic requirements of white radish planting in Weining,Guizhou,the whole machine design scheme of one row and two rows mode of white radish harvesting was determined.According to the needs of guizhou mountain operations,the walking tractor is selected as the power source of the small self-walking radish harvester,and the two main functions of the radish harvester are determined.Using Solid Works software to draw the harvester parts of the THREE-DIMENSIONAL model and assembly;The working principle and main technical parameters of small self-propelled white radish harvester were analyzed.(3)By analogy,the structural forms and working principles of key components of different root and stem harvesters are analyzed,and the soil loose and picking structure suitable for small self-propelled white radish harvester is determined.According to the results of radish pulling force test,the feasibility of loosening soil on both sides of radish root was determined.The fixed loose soil structure was selected,and the mechanical model was established to analyze the force of loose soil parts during operation.The force of loose soil shovel was 1200 N,and the force of loose soil shovel handle was 2600 N.By statics analysis,the maximum deformation point is 6.33 mm at the tip of the loose soil shovel,and the maximum stress is 171.42 mpa at the fixed point of the shovel handle.According to green radish pit one plant planting patterns,in order to ensure the green radish stem leaf parts contact with extraction and holding mechanism of friction,enough makes extraction bai luobo unearthed,choose to conform to the requirements of twin belt detaching holding mechanism,in the process of extraction,ensure that bai luobo movement direction and axial direction are consistent,determines the detaching clamping device with an Angle of 23 °horizontally.(4)An experimental study on drag and viscosity reduction of loose soil shovel was carried out by using the method of combining test and discrete element simulation.The Hertz-Mindlin with JKR moisture particle contact model was selected according to the characteristics of strong adhesion of yellow soil in hilly areas of Guizhou province.In order to make the discrete element simulation results consistent with the actual situation,the discrete element simulation parameters were calibrated based on the interaction between yellow clay and loose soil components,and the simulation parameter values under different soil moisture content were obtained.In order to reduce drag and viscosity,different types of loose soil shovel were used to loosen soil under different soil moisture content conditions,and the drag and viscosity reduction performance of chisel loose soil shovel with width of 40 mm was determined to be the best.Establish the platform test was carried out by digging operation test,the pressure sensor and data acquisition system are used to get the agency operations of digging dirt resistance and study the influence of different factors for operation resistance,including digging shovel on the digging resistance influence on the size of the Angle of the grave,when digging shovel in the Angle of 20 ° scarification least resistance.