| In maintaining the side slopes of the expressway,side slopes of ramp and greenbelts of interchange slope protection,the existing equipment is frequently unable to operate in this complex environment of complicated terrains and large slopes,which makes it difficult to complete the greening and maintenance work efficiently and with high quality.Furthermore,the existing hedge trimming equipment is mostly driven by internal combustion engines,which is not only seriously pollute the environment due to the exhaust gas,but also is extremely detrimental to the health of the operators due to the noise and vibration generated during the operation.Consequently,it is of great significance to develop environment-friendly hedge trimming equipment which can adapt to large slopes and complex terrains.For the purpose of completing reliably the design of the key structure of the electric crawler telecontrolled hedge trimmer,first of all,the author of the thesis made a detailed analysis of the working conditions of the hedgerow trimmer.Two design schemes were developed respectively for walking mechanism and tool frame,the walking mechanism scheme of electric drive rubber crawler chassis and the design scheme of four-link tool frame driven by electric putter were determined by analysis and comparison.Moreover,the author determined the traction performance parameters and structural dimension parameters of rubber crawler chassis by dint of analysis and calculation.In addition,by comparing the performance of different trimming tools,the author determined the performance parameters and dimension parameters of the pruning device.The author employed MATLAB to analyze the force of different shapes of the tool frame,obtained the relationship between the height of the tool and the force size of each component,and accordingly completed the design of the tool frame connecting rod and the selection of the electric putter.Finally,the author made three-dimensional modeling of the key structure,and verified the feasibility of the design scheme through kinematics analysis.Additionally,the author not only used the finite element analysis software Ansys Workbench to analyze the static mechanics of the assembly of the key structures under different working conditions,and accordingly completed the verificationof strength and stiffness of these key structures,but also made a lightweight design on the frame and tool frame with the lightweight design method for topology optimization and response surface optimization.The simulation results show that the structure design scheme of the electric crawler telecontrolled hedge trimmer meets the requirements of working conditions,and the key structures satisfy the strength and stiffness condition.Furthermore,the weights of the optimized frame and tool frame structure are greatly reduced,which lays a foundation for further research and provides a theoretical basis for the manufacture of the model machines. |
