Study On Key Components And Mechanism Of Pull-type Automatic Seedling Transplanter

With the continuous improvement of living standard,it’s shown that people’s demand of vegetables and other agricultural crops is increasing in recent years.The shortage of rural young labor leads to the high cost of vegetables and other agricultural crops.So far,it is still disadvantageous current situatiaon of vegetables planting which is dependent on time-consuming and laborious manual planting in China.Semi-automatic transplanting machine is gradually used to plant seedling of vegetables in domestic.But it is easy to lack seedling and repeat seedling by manual taking and transplanting.There are many kinds of seedling tray in China,and the automatic taking and transplanting seedling device is only suitable for the tray with certain specifications and materials.The above factors lead to the poor effect of the combination of automatic taking and transplanting seedling device and semi-automatic machine.Therefore,in order to improve the efficiency and quality of vegetable seedling transplanting,apply to the hole plates with different specifications and materials,and reduce the damage to the bowl.It is of great practical significance to research and develop an efficient trailer type automatic taking and transplanting seedling machine.The main research contents and results are as follows:Firstly,the a large number of data which is about the automatic taking and transplanting seedling device are consulted at home and abroad.The working principle,advantages and disadvantages of the automatic taking and transplanting seedling device are summarized,and aim at the goal of research and direction.Secondly,in order to decrease the damage of the seedling taking claw to the bowl,the mechanical property is carried out according to the compression characteristics of the bowl.Taking the wrapped vegetable seedlings as the research object,the compression performance of the bowl with different moisture content is experimentally studied.The function curve between the deformation‘s’of the bowl with different moisture content and the external load‘Fp’is fitted,and the elastic modulus‘E’,Poisson’s ratio‘μ’and Average density‘ρ’of the bowl with different moisture content are obtained.The mechanical property parameters which is obtained from the test provide a basis for the design of parameters such as the insertion depth of seedling taking claw,the area of clamping bowl and the angle of clamping bowl.Thirdly,the three-dimensional model of the trailer type automatic taking and transplanting seedling machine is constructed.It mainly includes the frame mechanism,power mechanism,seedling taking and transplanting mechanism,seedling feeding and planting mechanism,and the assembly of each mechanism is studied.The main component of seedling feeding and taking mechanism are studied.In order to decrease the damage of the seedling claw to the bowl,the mechanical characteristic parameters which is obtained from the test in Chapter 2 is used to calculate the clamping force.The force range is between 2.91N and 3.32N of clamping the bowl with different moisture content,and the deformation of the bowl is between 3.3mm and 5.67mm.Based on the clamping force and deformation of bowl,the structure of seedling taking claw is designed.The insertion depth is 35mm.The area of clamping bowl is 128mm~2,and the clamping angle of two seedling taking claws is 18°.Then,the kinematics and dynamics of incomplete gear-full gear reversing mechanism and incomplete gear-rack lifting mechanism are analyzed.The design requirements is satisfied which requires half a cycle of the motion and intermittent time of the reversing mechanism.The vertical displacement of the rack of the lifting mechanism satisfy the requirements in theory design.Finally,the dynamic analysis of the critical component of the machine is carried out by the finite element method.The maximum strain and stress values of the component are obtained under the working conditions,which satisfy the service conditions of the component,and verify the rationality of the mechanism design of the critical component.