Design And Study Of The Small-Scale Chain Type Deep Plowing Machine

Tobacco production of Guizhou Province is the second in China.In order to meet the agronomic requirements,save labor,reduce cost and increase efficiency in the corresponding production process of tobacco,it is critical to carry out the research and application of a mountain small deep tillage machine which has key technical problems existing in the tobacco production.Micro tillage machines have been used to plough land at present in mountainous areas of Guizhou for the terrain conditions.Soil in tobacco fields will become harden by using micro tillage machines for shallow tillage.It makes water and fertilizers to absorb difficultly,and affects the growth of tobacco seedlings directly,which finally impact the quality of tobacco leaves.Therefore,it is necessary to develop a small deep tillage machine for application in mountainous areas of Guizhou(tillage depth at least 25 cm).The main research contents of this article are divided into five parts:(1)Design of the small chain type deep plowing machine based on crawler type.Firstly,the design scheme was thought,and the structure,working theory and technical parameters were introduced.In addition,the basic structure,parameter calculation and mechanical analysis of the key components—chain deep plowing device and hydraulic control system were described in detail.then the design and three—dimensional models of other key components and were introduced.Finally,the entire assembly was checked interference and core device of the deep plowing machine—drive chain of deep plowing device was carried out movement simulation,which ensured the correct installation of the machine and the rational design of the machine function.(2)Structural static analysis of chain deep plowing device.Deep plowing device of deep—cultivating machine carried out stress analysis and geometric models of the device were imported the finite element analysis software ANSYS Workbench.The finite element analysis results were obtained by grid division and loading solution and discussed.Through the analysis,deformation of the device and the distribution disciplines of stress and strain were obtained,and the stress concentration part of the device was founded,which provided theoretical basis for improvement of the deep plowing device.(3)Structural dynamics analysis of chain deep plowing device.Firstly,the overview of the dynamic analysis was introduced.Secondly,the analysis of the harmonic response and the modal were discussed.The modal analysis and the harmonious response analysis of the chain deep plowing device of small chain type deep plowing machine based on crawler type were carried out.By analyzing the modal analysis of the machine chain deep plowing device,the frequencies of the first 6 orders were calculated and analyzed so that the good dynamic characteristics of the deep plowing device could be obtained.Through the analysis of the harmonic response,the stress—frequency response curve and the displacement—frequency response curve of the device were obtained respectively and the frequency values of the chain deep plowing device were obtained.It is concluded that the chain deep plowing device has a large stress and deformation response at about 29 Hz and 34 Hz.And these frequencies were also in the vicinity of the first and second order natural frequencies of the chain deep plowing plant.It shows that the deep cultivator studied in this topic will cause vibration in the first and second order modes in the operation.But the largest deformation is only 1.4mm,which is so small that the impact for the whole deep plowing device is very small.It can be ignored and thus it can meet the deep plowing requirements.The chain deep plowing device does not resonate at the operating frequency of 21.6 Hz.In this operating frequency the maximum depth of stress is 82.065 MPa and the maximum deformation is 0.84214 mm,which can meet the requirements of deep plowing.(4)Numerical simulation of tool cutting soil in the small chain type deep plowing machine based on crawler type.The tool and soil geometric model were established by Solidworks and ANSYS/LS-DYNA.Numerical simulation of soil cutting was carried out by explicit nonlinear dynamic analysis.The soil cutting process for single tool was analyzed,and its cutting force and cutting depth were analyzed.In order to analyze cutting force and provide the reference for numerical simulation of the soil to be cut by tool.(5)The first generation of the small chain type deep plowing machine based on crawler type was tested in several districts of Bijie city.It has good field through sexual,smooth surface after the operation,high reliability of the use and easy operation.The most critical thing was to achieve the design purpose of deep plowing machine,tillage depth of which achieved 25 cm,thus it was welcomed by much users and has been launched.