Design And Test Of Comb-type Safflower Picking Head Assembly

Safflower is an important economic crop.Filaments can be used as oil-bearing seeds,dyes,natural pigments,etc.However,the high cost and low efficiency of artificial picking severely restricts the development of safflower industrialization.Therefore,the mechanized harvesting of safflower silk is imminent.At present,the safflower picking machine is mainly a hand-held knapsack,but it has problems such as low efficiency and high labor intensity,and has not been promoted and applied.In this paper,according to the harvesting effect of the comb-type picking head developed by the research group at the same height,a comb-type picking head assembly is proposed.By arranging multiple sets of comb-type picking heads in the space,air blowing and air suction are used.The combination of collection methods is of great significance for improving the efficiency of filigree picking,reducing damage to flower bulbs and stems,and achieving mechanized picking of red filaments.The main research contents of the paper are as follows:(1)The safflower planting pattern and flower ball distribution in the plant were measured.It was found that as the height of the outer flower ball of the red flower plant decreased,the flower ball gradually distributed to the outside.After measurement and fitting,the outer flower ball changed with the horizontal position.The distribution pattern of the lateral flower ball decreases with height,and the inclination angle of the flower ball increases.The distribution model of the lateral flower ball inclination angle with height is obtained after measurement and fitting.According to the plant lodging test,the minimum allowable contact height of Yumin's thornless safflower was 250 mm.The limit clearance test showed that the limit clearance was 3 mm,and the comb picking head speed was 83 r / min.At the same time,a single comb-type picking head is ideal for harvesting high-level filaments.(2)Based on the characteristics of short safflower harvesting period and batch harvesting,combined with the harvesting plan of the relevant crops,the overall structure of the comb-type picking head assembly was designed,and specific parameters were designed for key components.According to the lateral flower ball distribution model,four sets of comb-type picking heads are designed to be uniformly distributed in the vertical direction in an arc shape,covering the safflower plants to achieve mechanized blind mining.According to the lateral flower ball inclination angle distribution model,combined with the comb-type picking head The installation position determines the installation angle of the comb-type picking head corresponding to the end cam.A comb-type picking head shield was designed according to the limit gap value and the flower ball shape parameters,and an air mouth was designed for the collection scheme to convey the filaments.(3)The force of the filaments on the picking teeth was analyzed to obtain the minimum wind speed required to transport the filaments,and simulate the air absorption set of the comb-type picking head assembly through the ANSYS / Fluent platform to obtain the wind speed at the air inlets of the five groups of air outlets.It is 7 m/s,and when the wind speed of the inlet of the jet pipe is 15 m/s,the minimum wind speed in the cavity is 2.9 m/s.The installation of the deflector and the wire brush can improve the airflow direction in the cavity,reduce the impact of the comb-type picking head rotation on the collection process,and complete the filament collection and transportation process.(4)The physical sample of the comb-type picking device was built,and the layout parameters of the comb-type picking head assembly were analyzed through experiments.The optimal layout parameters were obtained as follows: the top position difference was 198 mm,the middle position difference was 200 mm,the top height difference was 108 mm,and the middle height difference was 135 mm,the removal rate of the whole plant was 79.55%,the dirt rate was 1.52%,and the picking quality was 0.9.Through the test analysis,the optimal cam mounting angle is obtained as follows: from the top to the bottom of the assembly,the four sets of cam mounting angles are 2°,10°,25°,40°,respectively.Under the optimal parameters,removal rate of the whole plant was 77.27%,drop rate was 2.62%,and picking quality was 0.9.