Design On Grab Mechanism Of Round Straw Bundle Loader

China is a big agricultural country,and the annual output of straw is huge.Straw is a renewable biomass energy,which has extremely high usable value.Round bale collection of straw in the field is the weak link of straw harvesting operation,and is lack of machinery suitable for field collection.The existing straw bale picking machines are mature,but they are not suitable for ridge farming.In this paper,the factors such as harvesting season,working environment and direction of straw utilization were comprehensively considered,and the design scheme of loader grab suitable for ridge farming was put forward.Through the analysis of the existing machinery,a mechanical grab suitable for installing on a small loader was designed.The object of grab was round straw bundles of various sizes,which can complete loading and unloading of single or multiple round straw bundles at one time.The grab of loader was designed and optimized by drawing and analysis software.The main research contents were:(1)Through field investigation and literature review,the harvest and utilization of straw bales at home and abroad were investigated.Combining with the working environment in Northeast China,the advantages and disadvantages of round straw bale pickup vehicles at home and abroad were summarized.(2)The parameters of loader were selected and the small loader was chosen as the carrier for grab installation.And the extent of pressure subsidence of loader tyres on the ground was briefly analyzed,which met the requirements of type selection.(3)According to different sizes of round bundles,the shape of grab was designed with three lobes.Completed the design of the grab structure by using Catia software,and the hydraulic system of grab was designed in the hydraulic system of loader.According to the stress conditions of various working conditions of the grab,the static analysis of the main components of the grab was carried out by using Ansys Workbench software.The analysis results met the design requirements.(4)The grab was optimized by using Ansys Workbench topology optimization module,and lightweight improvement was made on the basis of ensuring the strength and stiffness of the structure.According to the improved results,the size of the grab structure was modified,and the static analysis of the modified structure was carried out.The final results met the design requirements.