Design And Tests Of The Multifunctional Track Transporter For Hilly Orchards

The hilly area is an important environment for orchard planting in China.Mechanized work is an important part of the orchard planting modernization in hilly areas.Traditional plain working vehicles can't adapt to work needs in hilly area,fruit work has become a major problem that needs to be solved in orchards mechanization for hilly areas.It's urgent to develop agricultural working machinery that adapts to hilly orchards in China.In order to solve the mechanized operation problems and improve the versatility and reliability of orchard transportation machinery in hilly areas,a multifunctional track transporter was designed for hilly orchards,which can transport and load apparatus to perform many works.In this paper,agricultural vehicle design theory,dynamic simulation and reliability design theory were applied to design the multifunctional track transporter;tests were employed to examine transporter's performance comprehensively.The main research contents were as follows:1.The design goals were proposed based on the operating environment and agronomic requirements.The engine was selected based on the needed power.The transmission scheme was selected with the walking system using mechanical transmission and power output system using hydraulic transmission;then the transmission ratio of the transmission system was determined and checked.The main parameters of track transporter walking system were determined and anti-overturn design was employed.The braking system and straight support legs were designed.The space layout was competed,and the centroid space location of this track transporter was determined by 3D model simulation.2.The running,passing,steering,and anti-overturn performances of the track transporter was simulated and analyzed.The running process was simulated and analyzed kinetically,and the influencing factors on the slip ratio and running deviation ratio were researched.The process of track transporter getting through gully and step was simulated and analyzed kinetically.The steering performance was simulated and analyzed kinetically,and the influencing factors on steering performance were researched.The anti-overturn performance was simulated and analyzed kinetically.3.The system reliability design for the multifunctional track transporter was conducted by using analysis and distribution of system reliability,Failure mode and effects analysis.The system reliability goals were proposed:Mean time between failures is 400 hours,the continuous working time exceeds 40 hours and the reliability is 0.905.System reliabilities were assigned according to the rating method.Subunits were checked according to the assigned reliability and it revealed that the results could meet the design goals.The system DFMEA analysis was performed and suggestions were made for the selection or design of subunits.Analyzed the reliability data,the reliability of the track transporter was better than that of the first-generation track transporter.4.The prototype's running,steering,passing,anti-overturn and braking performances were tested by experiments,and results showed that all the performances met the design goals.The running speed,slip rate,and running deviation ratio met the design goals.The experiments to test the minimum steering radius and the minimum passing radius were conducted.Passing rate tested on a way of standardized orchard is 100%which indicated that the inter-row passing rate is good.The track transporter was able to get through a 500 mm width ditch and get over a 110 mm height step.The centroid position was measured and the measuring and simulation results coincided with each other well.The static tilting angles of this prototype are greater than 25?.The prototype could be parked on an ordinary ramp and a soft and slippery ramp within 20?.The multifunctional track transporter has good passing,driving,anti-overturning,braking and parking performances in hilly orchards.Compared with the existing hill orchard transporters,this transporter has high system reliability and versatility.It can also complete many operations,save costs and improve both orchard transportation and operating efficiencies.It has a good practical application value for improving the technical level of hilly orchard mechanization.