Design And Experimental Study On The Key Components Of Pennisetum Giganteum Harvester

Pennisetum giganteum is a kind of Pennisetum grass,which has high nutritional value,strong resistance to adversity,wide adaptability and great economic and social value.The mycorrhizal industry has become a propeller to help poverty alleviation,increase production and prosperity,and promote mutual benefit and win-win results of many countries.However,with the rapid development of Pennisetum grass industry,the problems of low efficiency of artificial harvesting and high cost of harvesting have become the bottleneck of Pennisetum giganteum industry development.The only way to break the bottleneck is to develop the harvesting machinery of Pennisetum giganteum.As the key part of the Pennisetum giganteum cutter,the cutting performance of the Pennisetum giganteum harvester directly affects the quality and efficiency of the mechanized harvesting of the Pennisetum giganteum.First of all,according to the field environment and plant growth characteristics of Pennisetum giganteum,this paper designs the Pennisetum giganteum cutter and establishes the kinematic model of the Pennisetum giganteum cutter and the theoretical model of no leakage cutting,no contact with the cutterhead,and the matching of motion parameters.Through simple field test and statistical analysis of test data,two main factors affecting the head breaking rate of the Pennisetum giganteum cutter,the rotation speed of the cutter and the inclination of the cutter angle,were determined,and further research was carried out on the factors affecting the cutting quality and power consumption.Based on the physical and mechanical parameters measured by Pennisetum giganteum and the relevant formula of MAT_WOOD model in ANSYS /LS-DYNA software,a material model was established,which was in accordance with the transversely isotropic of Pennisetum giganteum,Finite element dynamic simulation was used to simulate the process of cutting stem with a simplified cutter.Then the single factor simulation of the movement parameters(cutter rotation speed)and structural parameters(cutter angle,knife cutting Angle and cutting edge Angle)of the Pennisetum giganteum cutter,the factors that affect the cutting power consumption(maximum cutting force,energy loss)and cutting quality(displacement difference between the xylem and phloem in the cutting process)and the destruction of the micro Pennisetum giganteum were found Preliminary understanding,Further adopt the response surface center combined design(BBD)test design method to simulate the cutter motion parameters and structural parameters,and use the statistical analysis method to establish the maximum cutting force,energy loss and xylem and The regression mathematical model of the displacement difference of the bast during the cutting process analyzes the influence of various influencing factors and their interactions on cutting power consumption and cutting quality.At the same time,the multi-objective comprehensive optimization was carried out to obtain the best combination of the influencing factors as follows: cutter speed 715 r/min,cutter angle 10 °,knife cutting Angle 29 °,cutting edge Angle At 25 °,the cutter's maximum cutting force is 166 N,the energy loss is 0.960 J,and the displacement difference between the xylem and phloem of the Pennisetum giganteum is the smallest during the cutting process.Finally,according to the optimization results and the actual use of the scene,the integrated cutter structure of the Pennisetum giganteum harvester is designed and the virtual prototype model is established.