Design And Optimization Of Working Parts In Upright Screw Ditcher

The ditcher plays a key feature role on national infrastructure projects, irrigation water conservancy projects, and forestry production. Using buried fertilizer is the only way which must be passed when developing pollution-free green food as well as improving the soil ecosystem. The screw ditcher is already widely used in orchard trenching for its compact form, flexibility and the feature of ditching short trench easily. The spiral cutter is the main working parts of screw ditcher. The design of movement parameters and structural parameters has a key influence on the soil cutting power as well as efficiency.The spiral cutter was designed in line with the requirement of fertilizing in garden The optimization of movement parameters and structural parameters for the spiral cutter was operated in this paper in order to reduce the cutting power of the screw ditcher.1.The helix equation which was used in establishing variable palpitation spirals in Pro/E Cartesian Coordinate System was set up combined with the formation principle of variable palpitation spiral and the operation mode of Pro/E.2.A kind of pillar type and double helix variable pitch spiral cutter was designed on the basis of requirement of ditching for burying fertilizer. The movement parameters were chosen initially.3.The movement and stress state of soil grain was analyzed when screw cutter milling the soil. The relation between cutter's structural parameters and critical speed of revolution for hoisting soil was founded. The spiral cutter which was designed fitted the requirement of hoisting soil well after checking The relation between cast soil distance and rotational speed as well as helical angle of outer vortex was ensured. The constrain condition of the optimization design was finally ensured.4.The simulation analysis on the soil cutting process was operated. Using ANSYS as the preprocessor, the screw cutter model and soil model were developed respectively, and then lodes and boundary conditions were defined respectively. The key words file for soil cutting was formed. Results solved by explicit formulation program LS-DYNA showed the stress and displacement distribution as well as the soil cutting power. The result of simulation analysis demonstrated that the designed spiral cutter could mill and hoist soil well. The soil cutting power solved by LS-DYNA was demarcated by theoretical formula, which showed little difference between the two results. The simulation analysis met actual conditions.5.Simulation orthogonal test in which the experimental factors were chosen by forward velocity, rotational speed and structural parameters was operated. The relation between soil cutting power and above-mentioned experimental factors was deduced after conducting the result figure through Excel, which could be a target function when operating the optimization design of screw ditcher.6.The mathematical model of optimization design for screw ditcher was developed combined with target function and constraint condition. The mathematical model was solved by fmincon which was a function for solving nonlinear programming problems in MATLAB. The optimization effect was notable. The stress distribution and deformation of blade was obtained finally.7.Simulation analysis on soil cutting process by cutting blade was carried out. The soil cutting principle was further revealed. Modal analysis of optimized spiral cutter was conducted and the first eight order modes was gained. The foundation was layed in order to further improve the operation quality as well as improving the operation efficiency in the further.