ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

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 hookhole 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 seedlayer 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 seedfilling 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 typehole wheel, the vertical height of the seedlayer 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 seedlayer thickness adjusting plate and the rotation speed of the celltype wheel in turn. Interaction between the length of cell and the rotation speed of the celltype wheel can not be ignored. The order of importance to the qualified rate was the vertical height of the seedlayer thickness adjusting plate, the rotation speed of the celltype 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 celltype wheel was 23.05r/min, the length of the hole was 7.00mm, and the vertical height of the thickness adjusting plate was 25.00mm, and then the qualified rate was 98.59%. The seed metering device under the optimized parameter combination was tested for seedfilling performance and seedmetering performance. The results showed that the qualified seedfilling 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 seedfilling 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 seedmetering rate was 90.03%, coefficient of variation of the seedfilling 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 seedmetering device. The wheat precision seed metering device of hooktypehole solved the problem of nonuniform 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.