Design And Test Of Press Seeder For Wide-seedling And Broad Sowing Of Wheat

In Huang-Huai-Hai region,wheat and maize rotation are the main cropping patterns.Before wheat sowing,many farmers use rotary tillage to prepare land for sowing seeds.Rotary tillage machine has high work efficiency and strong ability of breaking soil.But the quality of rotary tillage is not particularly ideal.The oil pore comparatively great and the soil is loose,This phenomenon will cause serious evaporation of soil moisture.and the consistency of sowing depth and uniformity of sowing depth are reduced.It will affect the normal growth of wheat and reduce the wheat yield.When the tractor works on loose soil,it will leave two very deep ruts,which will affect the sowing depth of wheat.The depth of seeds sown in the ruts is too shallow,the surface covered soil are insufficient,and the bottom soil is compacted by the tractor wheels,which will reduce the germination rate of wheat,make the growth of wheat seedling take roots difficultly,and the utilization rate of water and fertilizer is inadequate.In this paper,through carefully study and analysis of the characteristics of wheat seeders at home and abroad,investigation of wheat planting patterns in Henan Province,combined with the actual situation of wheat seeding in the region,in view of the problems existing in the before sowing soil preparation and sowing operations of wheat,the before sowing compact for wheat wide seedlings was designed,including the overall structure of the seeder,key pats and the compaction device,and the discrete element of the quality of the operation was also designed Simulation.This article mainly includes the following aspects:(1)Design the whole structure and key parts of the seeder.By retrofitting a compaction device at the front end of the seeder to realize the before sowing compaction and improve the quality of wheat seeding,the whole machine frame adopts the three-beam structure,the compaction device and the seeder frame are connected by the method of double-frame superposition,and the diameter of the press drum,the width of the screw blade and the pitch of the screw drum are calculated according to the depth and width of the rut.Force analysis was carried out to optimize the before sowing pressing device.Finally,the diameter of the rolling drum was 300 mm,the length was 950 mm,the width of the helical blade was 30 mm,the pitch was 280 mm,and the speed ratio of the gearbox was 15:24.The drill chooses the core drill,and the compaction strength is adjusted by changing the distance between the frame and the whole frame of the compaction device through the rotation of the hand wheel.(2)The trencher of the seeder is arranged according to the planting pattern of wide seedling belt,with four trencher in the front and eight trencher in back.When sowing,four broad seedling belts are formed.Each broad seedling has three wheat seeding rows and it is 8 cm width,the center distance of the seeding row is 12 cm,the center distance of two adjacent wheat seedling belts is 60 cm,and a 28 cm blank line is formed in the middle and later stages.The wheels of field management machinery can walk in the blank line of 28 cm.And come true the function of avoid rolling wheat and planting maize in the next crop,it is possible to sow in narrow rows,so as to realize 60 cm maize seeding with equal row spacing and avoiding stubble.(3)Discrete element simulation of sowing machine operation quality is carried out.Firstly,the simulation parameters of soil particles are calibrated by stacking angle test,and the appropriate simulation parameters are selected to simulate the whole sowing operation.The Hertz-Mindlin with bonding model is used to judge the compaction effect of the before sowing compaction device by the number of bond keys.Hertz-Mindlin(no slip)particle interaction model was used to simulate the disturbance of soil caused by trencher operation,which provided some data reference for arranging trencher and adjusting sowing depth in field sowing operation of press seeder before wide seedling band sowing.(4)A prototype was made and field experiments were carried out.The results were as follows:the bulk density of the soil under the pressure seeder before wide seedling belt sowing was increased by 0.193 g/cm3,which was more suitable for rooting and germination of wheat seeds;the soil consistency at the depth of 50 mm before sowing was 234.85 kPa,and at the depth of 100 mm the soil consistency is 337.73 kPa;after the operation of the compaction the soil consistency is 275.06 kPa at the depth of 50 mm,and the soil consistency is 554.75 kPa at the depth of 100 mm.The results of field experiments and late seedling emergence showed that proper suppression of soil before wheat sowing was beneficial to improving consistency of sowing depth and seedling emergence of wheat.