Design&Experimental Research On2BF-6Type Centrifugal Combined Seeder Key Parts For Rape

Rape is an important oil crop and economic crop in China, also could provide good plant protein and forage for animals, and the perennial cultivated area of rape accounts for more than a quarter of the world’s. Nowadays manual sowing and semi-mechanization planting are still the main operational modes,with the disadvantage of complicated procedures, high labor intensity,high cost, it is worse restricted in the enlargement of production scale and the increase of output benefits. With the recent development of agricultural machine in China, mechanical-type and air-assisted precision seeders for rapeseed have been invented to complete many functions including fertilizing,ditching, sowing in one operation, which have the advantage of higher efficient, lower consumption, less work time, however, many problems still exist, such as complex structure, heavy-weight,high power consumption. Therefore, it is necessary to conducted the furthermore study on precision seeders.2BF-6type centrifugal combined seeder for rape was developed to solve the problems, which was compact-sized and complete the teamwork including fertilization, rotary tillage, ditching, sowing,it could meet the agronomic requirements of rape in planting space,planting depth, row spacing,seed-fertilizer distance, fertilizer quantity, meanwhile, the work of management during the growth of rape could be reduced in thinning and the final singling. The main contents of this research were as follows:(1)The2BF-6type centrifugal combined seeder was developed.The working principle, key equipment and the structure features of the seeder were introduced to analyze, and obtained the major structural parameters and technical parameters in this article.(2)A centrifugal metering device was designed. According to the design principle, the parameters of some key components including the inclination degree of motor process, the diameter of seed holes and the inclination degree of seed holes were introduced to study in detail, and a new seed hopper was designed. In order to adjust the seed weight from seed hopper, a back taper and an arch breaker were designed in the metering device. Besides, the motion processes of rapeseed were also studied from the inner seed box to outer part, the mathematic models was introduced from the dynamic analysis and kinetic analysis.(3)The factors influenced the performance of the metering device were investigated and the results were analyzed. The experiments were conducted to investigated the relationship between rotation speed,seed weight inside the device, apiece row consistency variability coefficient, stability of total seeding quantity and the critical speed under the different conditions. Through single-factor and orthogonal experiments, the result showed that when the rotational speed was170r/min, and seed weight in the device was60g, the apiece row consistency variability coefficient of seeding quantity reached minimum value, which was8.48%. Field experiments presented that the2BF-6type centrifugal combined seeder could complete fertilizing, rotary tillage, ditching, sowing in one operation, and the results showed that the variation of planting uniformity was26.2%, the mean of planting space of seedling was92mm, which could meet the agronomic requirements of rape.(4)Structural compositions and working principle of rotary tiller were investigated in different blade arrangements to realize the tatter soil and buried stubble during the rotary tillage, and achieved the optimum arrangement of blades.(5)Motion simulations of rapeseeds in the metering device were studied to investigate the migration regularity by using EDEM. In order to achieve the regularity of rapeseeds when the centrifugal metering device was working,3D simulation models of the metering device had been established. The motion analysis of rapeseeds was achieved when the metering device was working in different working parameters. The relationships between seed weight inside the metering device and the critical speed, rotational speed and full seeding quantity were studied in the simulation experiments, the results showed that:with the increase of rapeseeds weight, the critical speed had a decreasing trend, while with the increase of rotational speeds, the full seeding quantity presented a increase trend. The simulation results were verified in the tests. The results showed discrete element method could be used to evaluate the performance of the centrifugal metering device. The results could be used to design the structure of centrifugal metering device and optimize the parameters.