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 view of the production requirements of ridge cultivation of rice and lack of related machinery and equipment in cold waterlogged paddy fields, low water and soil temperature and poor drainage, a ridging and leveling device suitable for cold waterlogged paddy field was developed. The device was mainly composed of a ridging roller, a micro-ridge opener and a leveling component to achieve large ridge drainage and micro-ridge water storage operations, which was conducive to cold waterlogged paddy field drainage and rice seed growth and development. According to the technical regulations of mechanical ridging rice cultivation in cold waterlogged paddy field, the key parameters of ridging roller, micro-ridge opener and leveling parts were designed. The radius of rotation of ridging roller was 560mm, the chamfer of conical surface was 28°, the width of micro-ridge opener was 50mm, the height was 40mm and the adjustable angle of leveling parts was 5°. Based on the DEM-FEM coupling simulation analysis, the optimal operating parameters of the device were determined. When the forward speed of the machine was 0.6m/s, the rotation speed of the rotary blade roller was 230r/min, and the rotation speed of the ridge roller was 120r/min, the soil backflow rate was 3.51%, and the stress and strain of the ridge roller were analyzed. The results of the field experiment showed that the average furrow depth was 160.03mm, the width of top of furrow was 174.84mm, the average width of top of ridge was 1888.89mm, the average flatness of box was 11.26mm, the average width of micro-ridge was 60.16mm, and the depth of furrow was 36.48mm. All indicators met the requirements of mechanized ridge operation in cold-waterlogged fields. The research can provide a reference for the design of ridge leveling machine in cold waterlogged paddy field.