| The cabbage is one of the most important vegetables consumed by Chinese residents because of its rich nutrition and high medicinal value.For a long time,cabbage planting has been dominated by artificial labor,with low production efficiency,high labor intensity,poor quality of transplanting and low survival rate,which limit the efficiency and benefit of cabbage production.In order to improve the quality and efficiency of the cabbage planting,this paper,based on the understanding of the present situation of the transplanting technology at home and abroad and the requirements of the agronomic planting of the cabbage,designed a kind of precision and efficient transplanting device of the cabbage pot seedling with the physical and mechanical characteristics of the cabbage pot seedling.The specific research contents are as follows:?1?The physical and mechanical properties of cabbage seedling were studied.Three different substrate ratios?M1,M2,M3?of Brassica oleracea seedlings with different substrate ratios?M1,M2,M3?were studied.When the seedling age was 40days,the physical and morphological characteristics?seedling height,seedling width and stem diameter?and drawing strength of potted seedlings were studied.Experimental study on pressure resistance and scattering characteristics.The results showed that the morphological characteristics of brassica oleracea seedlings were not significantly different under different substrate ratios.Comprehensive analysis showed that the growth and development of cabbage bowl seedlings were better when the substrate ratio was M3?peat:perlite:vermiculite=6:4:1?,and the water content of the seedlings was better when the substrate ratio was M3?peat:perlite:vermiculite=6:4:1?.When its moisture content is 55%,the pot of cabbage seedlings has the strongest stress resistance?5.303N?and the smallest pulling force?1.28N?.When taking seedlings by active grabbing,the compression displacement of the claw to the bowl should be less than 10.953 mm,so as to avoid the damage to the bowl when the bowl was picked up.The average scattering rate of three kinds of substrates from500mm scattering process was 2.2%,and there was no significant difference in the effect of three kinds of substrates on the substrate of seedling.?2?Research on seedling pick-up mechanism.Precision take in order to improve the success rate of seedling pick-up,seedlings as the main research targets,this paper proposes a ideal seedling pick-up trajectory,according to the requirements in seedling pick-up trajectory,based on the analysis of the seedling pick-up from existing ways,adopt active grab type seedling pick-up way,using the driving stability of planetary gear train and connecting rod mechanism,establish a set of planetary gear train pendulum lever mechanism motion model for seedling pick-up;VB6.0 was used to optimize the structure parameters and seedling pick-up trajectory of the seedling pick-up mechanism.A set of structural parameters were determined:the center distance between the solar wheel and the planetary wheel was the planetary frame OB length L1=50mm,the length of the connecting rod BC was L2=50mm,the length of the seedling pick-up arm DC was L3=120mm,the length of the rocker ED was L4=130mm,the distance between the center DC point of the seedling pick-up arm rotation and the end point F of the seedling needle was L5=180mm,the initial installation angle of the OA pole was?0=189°,the angle between OA rod and the AB was?1=262°,the angle between the connecting rod BC and the X axis was?2=163°,the angle between FC rod and the CG rod was?3=60°,the angle between the FC rod and CD rod was?4=214°,the coordinate position of E point was XE=76mm and YE=68mm.The three-dimensional design and simulation analysis of the seedlings pick-up mechanism was completed by Solidworks software,and the rationality and accuracy of the design of seedlings pick-up mechanism were verified.The whole track height of the seedlings pick-up mechanism was 128mm,the track length was 271mm,the approximate linear length of the seedlings pick-up section was 49 mm,and the seedlings pick-up requirements of the cabbage pot seedling were met.?3?Research on transplanting mechanism.In order to improve the verticality of bowl seedling planting and realize the high efficiency planting of bowl seedling,an ideal planting track was put forward.According to the requirement of planting track,this paper is based on the multi-connecting rod planting mechanism.Based on the stability of the planet gear train and the restraint of the slide track,a set of motion model of the slide track planting mechanism of the planet gear train is established by means of hole drilling and seedling release.The influence of the main structural parameters on the planting trajectory was analyzed by MATLAB.And the optimal combination of the structural parameters was obtained:the radius of solar wheel was R0=20 mm,the radius of middle wheel was R1=15 mm,he radius of planetary wheel was R2=10mm,the length of connecting rod BC was L1=100 mm,the length of rod CD on planting arm was L2=150 mm,the length of rod CF on planting arm was L3=80 mm,the length of duck bill planter FG was L4=140mm,the distance from point E to origin of coordinate O on a slide DE was L5=100mm,the angle of init ial installation of planetary frame OB was?0=45°,the angle between connecting rod BC and X axis was?1=45°,the angle between rod DC and rod CF of planting arm was?=176°,the angle between slide DE and X axis was?=108°.The virtual prototype design of the transplanting mechanism was completed by solidworks 3D modeling software,and the virtual prototype was imported into Adams.The rationa lity and correctness of the theoretical analysis of the transplanting mechanism were verified by simulation analysis in this paper.The height of the whole planting track was 302mm,the depth of transplanting was 65mm,the distance of transplanting plant was 365mm,which meet the agronomic requirement of transplanting cabbage seedling.?4?Transplanting mechanism and transplanting mechanism of cabbage seedling in pot were studied.In order to check whether the working performance of the seedlings pick-up mechanism and the planting mechanism designed meets the design requirements,a prototype of transplanting a bowl seedling with a seedlings pick-up mechanism and a transplanting mechanism was manufactured,which was equipped with a seedlings pick-up mechanism and a transplanting mechanism.The transplanting experiment of cabbage seedling in pot was carried out with the success rate of taking seedling and the stand degree of potted seedling as the main evaluation indexes.The results showed that when the transp lanting frequency was 74 plants/min,the successful rate of seedling selection was 95.57%,the eligible rate of straightness was 92.19%,and the excellent and good rate was as high as 89.22%.Compared with the existing transplanting equipment,the results can meet the design requirements of accurate seedling extraction and high efficiency transplanting machine for cabbage bowl seedling transplanting. |
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