Abstract:
Film-mulching cultivation technology could significantly improve the growth condition of crops and increase the economic benefits of agricultural production. However, the residual film in soil is very difficult to degrade, and there is no effective recovery method, resulting in the amount of residual film in farmland soil gradually increased. The residual film currently has a serious impact on the ecological environment of farmland soil. To solve this problem, domestic scholars have devised a variety of residual film collectors. The design of film removing device was one of the key points in the development of the residual film collector. However, the existing residual film collectors mainly adopts the structure of pneumatic, telescopic rod tooth and rotary scraper, which could easily cause secondary winding of residual film during the film removing process. Thus, a film removing device of clamping finger-chain type for residual film collection was designed in this study. The device was consisted of scraper assembly, crank-rocker mechanism and film-impurity separation mechanism, which could complete the work of film removing, film-impurity separation, and film transport at one time. In order to increase the contact times between the finger and the scraper when the clamping finger-chain moved upward, a double-layer arrangement structure of scraper was adopted in the scraper assembly, and the structural parameters were designed through the analysis of the operation process. The ADAMS software was used to simulate and analyze the motion trajectory of the endpoint of the scraper, and the length of each rod and the mounting angle of the crank-rocker mechanism were designed. Through the force analysis of residual film, the mounting position of the crank-rocker mechanism was determined. Through the kinematics analysis, the maximum value of the angular speed ratio between the upper film collecting wheel and the crank when the fingers were not scratched was obtained. In order to achieve the film-impurity separation and film transport, a film-impurity separation mechanism with reciprocating swing type was designed, and the structural parameters of related components were designed based on the operation mechanism analysis and performance tests. The field experiments results showed that the residual film recovery rate was 93.12%, the film removing rate was 98.2%, and the impurity rate was 16.08%, when the travel speed of the collector was 4.5 km/h, the width of scraper was 100 mm, the horizontal mounting distance between the rotation center of crank and the center of upper film collecting wheel was 290 mm, the vertical mounting distance between the rotation center of crank and the center of upper film collecting wheel was 200 mm, the angular speed ratio between the upper film collecting wheel and the crank was 0.5, and the mounting distance of the bar in film transport sieve was 50 mm, The results indicated that the film removing device could meet the field operation requirements of the residual film collector. The research can provide the basis and reference for the development of relevant residual film collector.