Development Of Stump Cutting Machine With Adjustable Cutting Height For Herbal Cultivation Hybrid Mulberry

Mulberry flat stubble harvesting machinery has developed greatly in China in recent years,but most of them can only be adapted to the harvest conditions in a specific area.The mulberry plots in our country are scattered,the topography of the planting is complex,including flat land,mountain land,slope land,etc.,and the mechanical adaptability is not strong.There is no uniform planting mode,and the application of machinery is limited by the row spacing and density of mulberry trees.Different types of mulberry gardens have different requirements for mechanical operations.Therefore,the requirements for flat stubble are also different,and the stubble height is required to be between 50 mm and 300 mm,or even higher.Most mulberry machinery cannot meet the requirements of different mulberry gardens at different heights.On the basis of mechanical characteristic test and virtual simulation technology,a herbaceous mulberry flat stubble machine is designed.This machine has a broad application space and has a very good prospect of promotion.According to the principle of combining agronomic and agricultural machinery,a herbaceous mulberry flat stubble machine was designed.The main work contents are as follows:(1)Study the mechanical properties of the herbal mulberry boxing part,and use the universal testing machine to carry out shear,compression and bending tests to obtain the mechanical properties of the herbal mulberry boxing part It provides the basis for the establishment of the working cutting parameters of the machine,and also provides the parameters for the subsequent sawing modeling simulation.Provide effective reference data when developing and designing the same type of machinery in the future.(2)Use SolidWorks to build a three-dimensional prototype model,and then combine Hypermesh and LS-DYNA for simulation analysis.It is determined that the better working state of the machine corresponds to the first gear high throttle.In this state,the driving speed is 0.4 m/s,the speed is 3200 r/min,the corresponding linear speed is 50 m/s,and the cutting driving speed ratio is ? = 125.(3)Design the whole machine plan,main structure and parameters of each part.Query relevant data and conduct theoretical calculation analysis to determine key parameters.Using SolidWorks three-dimensional design software to design the structure of the flat stubble machine,mainly including power mechanism,walking mechanism,rotary saw blade cutting head and so on.The key mechanisms of this design mainly include ground clearance adjustment mechanism,screw adjustment mechanism,friction disc steering mechanism and disc saw and cutting table.The design parameter values are mainly wheelbase 500 mm ~ 650 mm;header harvesting width is 650 mm;height adjustment range is 50 mm ~ 300 mm;the working part of the header of the flat stubble machine is a circular saw,diameter is 300 mm,speed The maximum is 3200 r/min,the maximum linear speed is 50 m / s,corresponding to the cutting travel speed ratio ? = 125;the designed machine travel speed is 0.72 km/h ~ 3.27 km/h;the conveyor chain speed is 1.05 m/s;saw The flake angle is 14°.(4)Analyze the stability of the horizontal stubble machine up and down the slope and the horizontal driving on the slope.Through analysis,the critical angles of tipping and slipping during vertical and horizontal driving are obtained;The coordinates and related parameters of the whole machine are analyzed and calculated,and the coordinates of the center of gravity of the sprayer are calculated to be 994 mm,478 mm,30 mm;the calculation shows that when walking on the stubble field and the adhesion coefficient of the walking wheel ? = 0.6,the longitudinal uphill limit Tilt angle 31.8°,longitudinal downhill limit tilt angle 74.3°,longitudinal uphill slip angle 30.7°,longitudinal downhill slip angle 24.2°,lateral driving limit tilt angle 61.9°,lateral driving slip angle 28.4°,in line with design Claim.(5)In the final prototype test,the maximum speed that the circular saw can reach is 2830 r/min.The test results show that when the first throttle is high,the driving speed is 0.35 m/s,the maximum linear speed is 44 m/s,and the cutting driving speed ratio ? = 125.7,that is,when the circular saw speed is 2830 r/min,the stubble The damage degree is 2.54.At this time,the value of the stubble damage degree is the smallest,which is the most suitable working state,which is the same as the simulation result.The machine is suitable for the flat stubble work of herbaceous mulberry.After harvesting,the stubble has little effect on the subsequent growth of the mulberry strip.The working efficiency is high and the quality of the stubble meets the requirements.