Abstract:In order to solve the problem of poor uniformity of wheat precision seed metering device used in wide seedling strip, combined with wheat precision seeding technology, a kind of hookhole type wheat precision seed metering device used in wide seedling strip was proposed to ensure uniform distribution of seeds in rows, and the seeds in rows were not scattered. The design and theoretical analysis of key parameters were carried out. Single factor test on the effects of the horizontal distance of the seedlayer thickness adjusting plate, the arrangement of the hole, the number of hole, the inclination angle of the hole and the inclination angle of the bottom plate in seed box on seedfilling performance were studied by EDEM discrete element software, and then the parameters were determined. On this basis, the multiple quadratic regression rotation orthogonal combination test was carried out with the rotation speed of the typehole wheel, the vertical height of the seedlayer thickness adjusting plate and the length of the hole, and then the test data was analyzed by Design-Expert 8.0.6 software. The regression model and the influence of factors on the index were obtained. The influence relation of factors on the single rate was determined and the order of importance was the length of hole, the vertical height of the seedlayer thickness adjusting plate and the rotation speed of the celltype wheel in turn. Interaction between the length of cell and the rotation speed of the celltype wheel can not be ignored. The order of importance to the qualified rate was the vertical height of the seedlayer thickness adjusting plate, the rotation speed of the celltype wheel and the length of hole in turn. Based on the regression model, the parameters were optimized. The optimization results of the target parameters showed that when the rotation speed of the celltype wheel was 23.05r/min, the length of the hole was 7.00mm, and the vertical height of the thickness adjusting plate was 25.00mm, and then the qualified rate was 98.59%. The seed metering device under the optimized parameter combination was tested for seedfilling performance and seedmetering performance. The results showed that the qualified seedfilling rate was 98.01%, and the relative error between the test verification result and the simulation optimization result agreed well. The reliability of the simulation optimization result was verified. The variation coefficient of the seedfilling qualified rate among the four rows of seeders was only 1.20%, and the variation coefficient among the rows of the wide strip was small; the qualified seedmetering rate was 90.03%, coefficient of variation of the seedfilling qualified rate between rows was 1.50%, coefficient of variation of uniformity in a row was 16.54%. The performance of seed metering was much better than that of existing common grooved seedmetering device. The wheat precision seed metering device of hooktypehole solved the problem of nonuniform distribution of random scattered distribution in outer groove wheel seed metering device used in wide seedling strip. The research results provided a reference for the design of the wheat precision seeder used in wide seedling strip.