亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

Cottonstalk is an important renewable resource. With an annual output of 31.5 million tons, China is rich in cottonstalk, which has great potential economic benefits. Cottonstalk uprooting is laborintensive and rollertype uprooter is not suitable for cotton planting patterns in China. Dentate disc cottonstalk uprooting device has good application prospect. Relevant research focused on cottonstalk mechanical properties, uprooting force and uprooting device design, but lack of further research on cottonstalk movement analysis and uprooting mechanism. It is urgent to carry out a deeper research on the technology and machinery of cottonstalk uprooting. In order to solve the problem of omission, fracture and low pulling out rate of the cottonstalk uprooting machine, a dentate disc multirow cottonstalk uprooting device was designed based on the electrohydraulic control technology and corresponding tests were taken. ADAMS was used to simulate the movement of the device and further reveal the cottonstalk uprooting mechanism. Under two operation modes of the device (speed locking mode or speed ratio locking mode), univariate analysis and multivariate regression analysis method were used to investigate the influence of dentate disc circumference speed, tractor forward speed and speed ratio (dentate disc circumference speed by tractor forward speed) on the omission, fracture and low pulling out rate of cottonstalk. The results showed that the device could meet the design requirements which can carry out cottonstalk uprooting test under various conditions. The magnitude, direction and duration of the uprooting force could affect the uprooting results. When the clamping time was less than the uprooting time, it would easily cause cottonstalk fracturing. Increasing the dentate disc circumference speed would contribute to a low omission rate. Speed ratio and dentate disc circumference speed both had significant impact on the pulling out rate, omission rate and fracture rate of cottonstalk. The speed ratio was the most critical factor which determined the pulling out rate of cottonstalk. The optimal speed ratio range was from 0.55 to 0.80, and the optimal dentate disc circumference speed range was from 0.24m/s to 1.10m/s. When the dentate disc angle was 6°, the tractor forward speed was 0.85m/s, and the speed ratio was 0.75, the pulling out rate of cottonstalk reached its maximum value of 93.89%, the fracture rate was 4.43% and the omission rate was 1.68%. The research result could provide a theoretical basis for optimizing structure and performance of cottonstalk uprooting machine.