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

According to the deficiencies in uneven soil compaction and insufficient intensity in hilly region，the bidirectional profiling and strength adjustable press device was designed based on the hilly agricultural mechanical characteristics, which mainly consisted of profiling adjusting mechanism，strength adjusting mechanism and press wheel. The interaction model of soil and press wheel was established. Force analysis of press wheel was carried out to determine working process of press wheel. Force analysis of press device was carried out to determine the reasonable range of spring deformation (suppression of strength). The contrast test was done to verify the device performance of profiling, and the orthogonal tests were done to verify the hilly terrain repression wheel, soil interaction models along the correctness of draft force (activity-based costing) and ratio of root to shoot (crop growth state), and the factors affecting the changing rule of performance test. The effects of device under type of press wheel， intensity of the suppression and forward velocity were studied. In order to achieve the purpose of balancing the various indicators, the best combination was determined by using comprehensive weighted scoring method. The results of orthogonal tests of L9(34) showed that the primary sequence of factors was as following: press wheel, suppress strength and forward velocity, and the optimal combination was: rubber press wheel, spring deformation amount of 20mm and forward velocity of 1m/s. Under the conditions, the rate of draft force was 22.3N, and the ratio of root to cap was 0.271. The result of contrast test showed that profiling press device was good in ensuring the uniformity of soil compaction. The result provided valuable information for the design of press wheel of planter.