Design And Experiment Of The Pneumatic-spoon Combined Corn Precision Seed-metering Device

Corn is one of the main food crops in our country, which has great significance on food production safety. Most areas in China have already implemented the corn planting mechanization,the corn planting mechanization of widely used on big seeding rate,such as drilling and dibbling,which using this manner to ensure full stand, this not only waste of seed but also increase the thinning labor costs. To achieve the goal of high yield, we must attach much importance to the combination of agricultural machinery and agronomy, achieve precise seeding.Corn precision seeding mechanization not only can save the and seed, but also can ensure the planting distance is consistent with the sowing depth, which ensuring seeding healthy and tidy, increasing crop yields finally.Corn precision seeding mechanization is the development direction of corn planting technology. Precise seeding is divided into aspirated-air type and pneumatic type. Corn precision drilling in our country basically used mechanical precise metering device, the mechanical precise metering device is strict in seed size, shape, sowing precise inaccurate,injury rate highly and not suitable for high-speed operation. Pneumatic type metering device due to advantages such as good adaptability to the seed, adapting to the high-speed operation, which has become the developing direction of precise metering device. This paper combined with the characteristics of several mechanical and pneumatic type, designed a kind of pneumatic-scoop precise metering device.First we select the three kinds of corn seeds for experiment, and the physical and mechanical characteristics of three kinds of seeds have been studied in detail. Then studied which Combining with the working principle and structure of pneumatic-scoop precise metering device,making a detailed theoretical analysis on the pore structure and size of pneumatic-scoop precise metering device,using reliability design methods studied determining the size of pore, established the mathematical model of seed filling pore.Using 3d software modeling and making metering device prototype in factory, and taking the trial production of pneumatic-scoop precise metering device to the bench test. Testing the pressure and speed of s1,s2,s3,s4,four size of pores.Tests show that in low speed operation, s3 has the best effect, which required pressure slightly higher, but in high-speed operation, sowing serious leakage;s4 shows the best adaptability in seed filling and high-speed operation, the minimum required pressure, but replay index is higher at low speed.Through experimental study finally concluded that the pore size for s4, of which the average qualified index of pneumatic-scoop precise metering device is highest in 4 ~ 12 km/h operating speed, seed filling shows the superior performance, adapting to the high-speed operation better.