| Nowadays, China, ascending to the second-largest grape producer in the world, has become a large grape-producing country. The protection for grapevines, as an essential work in the process of grape planting, is a hard task with intensive labor and bad conditions, a task that is expenditure of time and effort, which accounts for 30 percent of the total work of the management of grapevines. And currently, limited by some conditions like terrains and acreages of vineyards in our mainland, it is hard to spray pesticides by operating those large-scale and middle-sized orchard sprayers in vineyards. So, manual operations are still in the dominant position in the process of prevention and cure of vine diseases and insect pests by adopting the high-flow spray technology and the coarse droplet spray technology, which leads to low level of mechanization and long-term growth cycle. And the wastage and drifting of pesticides become worse, attributing to the lower utilization and poor spray effect. To make protection for insect diseases, orchard workers have to increase the amount of pesticide, which aggravates the pollution of the orchard environments. Thus, it is of great significance for China to study a new small-sized tractor-loaded sprayer with small turning radius, high flexibility, and good effort of spray which is propitious to the trellis-type vines in mainland.Then after studying large quantities of domestic and foreign materials and doing some field researches on some vineyards at home and abroad, a axial flow sprayer powered by small-sized four-wheel tractors, is flexible and fit for the trellis-type vines. The innovation and upgrading of its structure was made on the basis of the traditional orchard sprayer. Through fluid simulation calculation of the return guide vane by using Fluent(a fluid simulation software), structures of circular return guide vanes have been upgraded so as to distribute the air curtain, which was formed by high velocity airs, on both sides of the vane. By doing this, it is better to achieve the functions of atomization and transmission of pesticides. The spray distance can be changed through increasing electric control width adjusting part when the sprayer was working, which alloys spray nozzle in best spray distance for different planting scale and the same area in different areas of the country of different growth vine, so as to achieve the best effect of plant spray protection. The specific research works are as follows:The structure of the overall scheme was designed depending on rear output shaft as power source of small four-wheel tractor, including design and improvement of the butterfly guide plate, selection of diaphragm pump and axial flow fan, design and type selection of triangle belt transmission system, design of electrical control width adjusting part and high pressure spray system, etc.2D diagram of part of the structure was drawn by AutoCAD,3D modeling of complete machine was done by software Pro/e and with the help of fluid simulation software Fluent to fluid simulation the design of butterfly guide plate. Then continuously improve optimization of butterfly guide plate structure through collecting and analyzing of the main parameters and determine the optimal solution through the demonstration of the machine design scheme.On the basis of theoretical analysis and design, the prototype trial and the performance test was completed. The experimental results showed that when there is wind than when there is no wind, the droplet deposition was increased by 48.9%; Liquid droplet penetration, the presence of wind feed type, liquid in the upper plant, droplet deposition volume increase 16.6%. The coefficient of variation decreased 18.1%. Liquid droplet penetration, the presence of wind feed type, liquid in the middle plant, droplet deposition volume increase 26.9%.The coefficient of variation decreased 7%.Liquid droplet penetration, the presence of wind feed type, liquid in the lower plant, droplet deposition volume increase 29.5%.The coefficient of variation decreased 12.7%.Liquid adhesion rate, the liquid in the plant leaf attachment 66.7%,dorsal attachment rate was 41.7%,Required to meet the "NY/T 1992-2006 breeze orchard sprayer job quality" liquid coverage requirements on fruit trees is not less than 33%. Droplet diameter, the presence of wind sent the formula, the average droplet diameter is reduced by 122.3 ?m to 90.3?m, droplet uniformity DR value increased by 14%, improve the uniformity of the droplets. |
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