Design And Experiment Of Sowing Depth Control Device For Potato Planter In Hilly Lands

China is a large country for planting potatoes.Increasing the level of sowing mechanization of potatoes is of great significance to the increase of potato production.In the s outhwest mountainous area of the potato planting area with the largest potato planting area in China,the topography and landforms are mostly hilly and mountainous,with slopes in both horizontal and vertical directions,and the plots are scattered and irr egular in shape,with diverse planting patterns,single agricultural machinery products and small agricultural machinery.The main,and mostly artificial sowing,the level of agricultural mechanization is backward.Foreign potato planters use a large number of advanced technologies such as automatic control,hydraulic system for seed supply,seeding electronic monitoring,etc,with a high degree of intelligence and precision.Foreign potato planters use multi-factor profile adjustment in large multi-row(more than 4 lines).The sowing depth of sowing monomer meets the requirements of multi-row wide potato sowing quality,but it is not suitable for small plot operation in hilly mountains.The domestic potato planter with profiling sowing monomer is mainly for large-scale cultivation agronomic requirements in plain areas.It is not suitable for the soil characteristics and natural environment of hilly mountainous areas in China,but the small potato planter suitable for hilly mountain areas mainly relies on the overall profiling of the ground wheel,the application of the single-shaped profiling mechanism is less,and the consistency of the sowing depth is poor.Therefore,the level of mechanization of potato planting in hilly areas is relatively backward and th e yield of potatoes is not high.In view of the above problems,this article studied the potato sowing depth control device,and designed the main structure and conducted reasonable theoretical analysis,model simulation and experimental research.Related research results:(1)The overall scheme of the sowing depth control device is determined to control the sowing depth jointly by the profiling mechanism and the depth-limiting wheel.The parallel four-bar profiling mechanism is used to design the parallel four-bar profiling mechanism with a rod length of 400 mm.The traction angle is 15°,the initial traction angle is 0°,and the lateral width is150 mm.The configuration of the front profile depth-limiting wheel is adopted,the diameter of the depth-limiting wheel is 200 mm.In order to reduce the soil disturbance and improve the consistency of the trench depth,a sliding knife ditch is designed.And finally determined the width of the opener is 230 mm and the height is 160 mm,and the angle of the ditch blade is 60°.(2)Through the motion analysis of the sowing depth control device in the working process,the soil rheological model is introduced to obtain the mathematical model of the device’s profiling process,and its approximation is regarded as a single-degree-of-freedom damped vibration system.Finally,the transfer function of the model is obtained by Laplace transform,and the trench depth at different topography can be obtained by solving this function.The Lsim function in MATLAB software is used to simulate and solve the trench depth,and the rationality of the device design scheme is finally verified.(3)Theoretically analyze the movement law of the potato sowing depth control device,establish a stability model of the trenching depth,and initially determine the main factors affecting the consistency of the sowing depth,including the initial traction angle,spring stiffness and the machine’s working speed,which will lay the foundation for the determination of the parameter range in the subsequent single-factor test.(4)The field test verified the sowing depth control device can solve the problem of poor profiling effect and poor consistency of the sowing depth of the potato planter in the hilly mountain.It clarified the best working parameters,the initial traction angle was 0°,the spring stiffness was 10N/mm,and the machine’s working speed was 1 m/s.The corresponding optimized test for ditch depth qualification index was 96.6%,ditch depth variation coefficient was 8.9%.They are both better than the national standard and meets the requirements of the operation.The potato sowing depth control device designed in this paper can effectively improve the consistency of potato sowing depth in hilly and mountainous areas in the southwest mountainous area,and it has certain reference value for the design and optimization of potato precision sowing monomer.