Design Of The Integrated Platform For Lifting And Unloading Of Wheeled Conveyor In The Mountain Orchard

Fruit industry is one of the pillar industries of Chinese rural economy,which plays an important role in the adjustment of agricultural industry,increasing farmers'income and foreign exchange.The fruit-picking and fruit tree pruning are an indispensable part in the management of orchards.At present,In these parts of the orchard,it relies mainly on human labor.In the fruit harvest,due to its relatively concentrated maturity,the time is short and the labor intensity is great.If fruit cannot be picked and transported in time on rainy days,fruit farmer will cause a great economic loss.For some large orchards,artificial labor is more difficult to meet its needs.At the same time,in the process of fruit-picking,the fruit trees are high and it's dangerous to be able to leave the ground.There's a relatively simple function of what's available in the country,and if you buy a full set,it costs a lot of money and that's a lot of economic pressure on many small orchards.Orchards in foreign countries have sophisticated products with mature technology,but there are very expensive and unable to be paid for small orchards.Therefore,the development of a multi-functional orchard machinery is very meaningful.In this paper,based on the laboratory research and development of gasoline engine driving wheel conveyor,it designs a working platform integrating lifting and unloading function,and establishes a more simple and reasonable design method by improving the design method of the traditional scissor-lift analogy method and the optimization design of engineering mechanics and mechanical design.Firstly,the relative size parameters of wheeled conveyor are determined.According to the application,the overall design and the size parameters of the platform are determined.The mechanical model of the mechanism was establishe and the force analysis was carried out to obtain the force expression of each hinge point of the cylinder thrust and the scissor arm.The three-dimensional model of platform,shear fork lifting mechanism and switch mechanism etc are applied by the Solidworks and the interference shearing fork is analyzed after assembling.The model is imported into ADAMS.its materials,quality attributes,constraints and loads are added.The dynamic simulation analysis is carried out.The results show that the platform lifting height is 2010 mm,lifting angle is 55.17°which is greater than the rest and the maximum lifting force of oil cylinder is 35075N,the maximum hinge point of the shear arm is O₁,whose value is 81440N and the peak value of each hinged point appears in the initial position of lifting.Furthermore,based on ADAMS simulation results,the parameterized model of the platform is established.According to the optimization goal,three design variables were created and after parameterization of the components and the moving pairs,the optimization analysis was conducted and the performance evaluation curve of the lifting mechanism was optimized.The results show that,after the optimization,the lifting force of the lift is 31370N,which is reduced by 10.5 percent and after optimization,the curve of lifting force is relatively gentle with time,which is conducive to the stability of lifting process.Based on the analysis of the forces of ADAMS simulation,it is determined that the platform is at the beginning of the initial transient state.The shear arm model was imported into ANSYS to carry out property definition,grid division,addition of boundary conditions and load and the stress cloud diagram,strain cloud diagram and total deformation cloud diagram of the fork arm were obtained.The analysis results show that the maximum stress is 219.08MPa,the maximum deformation is 0.3375mm and the platform shear arm meets the requirements of rigidity and strength and provides the coMParison data for the subsequent test results.Finally,the dynamic stress test system of the shearing fork arm is constructed to study the dynamic stress of the shear fork arm and the stress curve of the key part of the shear arm is obtained.The test results show that at each point,the stress maximum appears to be connected to the top of the piston rod and the connecting rod to the shearing arm,which is172.8 MPa and the stress values of the other measuring points are within 60MPa and in the stress curve of each measuring point,most of the stress peaks occur in 2.5-3s.CoMParing the test results with the static analysis,the results show that the error of the measurement points in addition to the 7th and 9 points is slightly more than 20%,and the coMParison error of the other measurement points is within 15%,which further verifies the accuracy of the simulation analysis model.By measuring the prototype,the lifting height and lifting angle are determined to meet the design requirements.The basic performance of the platform was tested,and the results showed that the lifting speed was 0.09m/s when the platform was empty,and the full load decreased speed was 0.38m/s,which meets the design requirements and when the platform is fully loaded,the lifting time is 18.37s,and the decrease time is 9.32,which meets the requirements and the settlement amount of the platform is very small and negligible.