Development of unilateral cleaning machine for grapevine buried by soil with rotary impeller

Abstract: Due to China's unique climate and geographical conditions, compared with foreign countries, ours grape planting requires two additional operations, which are burying soil to prevent cold in winter and cleaning soil in spring, and the degree of mechanization in the spring soil-cleaning operation is relatively low. The design and development of grapevine soil cleaner is of great significance to the industrial development of the grape planting, so aiming at the problems of low efficiency and low mechanization of artificial soil cleaning operation of grapevines in the main grape producing areas of northern China in spring, this paper design a grapevine soil cleaner with rotary impeller for unilateral cleaning soil and its operation principle was analyzed. The machine is mainly composed of the frame, the soil scraper parts, the rotary impeller part, the screw shaft of levelling soil parts, and the depth limit wheel and so on. Among them, the soil scraper parts, the rotary impeller part and the screw shaft of levelling soil parts are the main soil cleaning parts of the machine. When the machine is working, the soil of the upper part of the grapevine was scraped to the rows by the soil scraper parts, the rotating impeller parts removes the soil on the side of the grapevines away from the cement pillar and the soil that scraped by the scraper parts, and the removed soil is again transported to the rows and evenly spread between the rows of grapes by the screw shaft of levelling soil parts, through the cooperation of these mainly parts, the soil on upper part of the grapevine and on the side far from the cement pillar can be removed to the middle of the grape rows, in order to re-use the buried soil in the winter and the late plant protection machinery to walk between the grape rows. During the working, the tractor hydraulic three-point hitch and the depth limit wheel are used to adjust the height of the machine from the ground. Modeling the machine in 3D software Solidworks. In order to reduce the amount of simulation calculations and improve simulation efficiency, this machine model is appropriately simplified and all of parts were scaled down to 0.5 and then imported into the EDEM. The whole simulation test environment was also scaled down to 0.5 correspondingly, and the simulation model of soil particle was established by using EDEM software to simulate the working process and verified the feasibility of the principle of the machine. Then, the forward speed, impeller rotary speed, and the screw shaft rotary speed were taken as the factors, and the distance between the inter-row soil distribution center line and the inter-row center line was used as an indicator to conduct the orthogonal experiments, the minimum value of distance between the inter-row soil distribution center line and the inter-row center line is used as the optimal index, as a result, obtaining the best working parameter combination of the machine: impeller rotary speed 420 r/min, screw shaft rotary speed 300 r/min, forward speed 1.2 m/s. Under this condition, the distance between the inter-row soil distribution center line and the inter-row center line in EDEM is 44 mm. Finally, manufacturing physical prototypes and conducting field tests, and the results of field tests were compared with the result of simulation experiments, the results show that the field tests' results are basically consistent with the simulation optimization results. The soil on upper part of the grapevine and on the side far from the cement pillar was evenly laid in the middle of the rows of grapevine. The relative error between field tests and simulation tests is 15%, which satisfies the operation requirements for unilateral soil cleaning of grapevines. This study provides a reference for the development of other types of grapevine soil cleaner.