Design of imitating manual harvesting device for edible sunflower

In most areas of Xinjiang, edible sunflower is harvested in stages by means of transplanting plates for drying and taking plates for threshing. In some areas, edible sunflower harvesters are used for field operations, and problems such as edible sunflower plate leakage and grain loss exist in the process of harvest, which seriously hinder the development of edible sunflower scale and industrialization. In order to solve these problems and improve the harvesting efficiency of edible sunflower machine, this paper conducted a field survey on planting mode and biological characteristics of the edible sunflower in Xinjiang, and summarized the harvesting mechanism of edible sunflower. Starting from the operation path of manual harvesting sunflower tray, and combining with the requirements of field harvesting, a kind of collecting station for edible sunflower was designed. Field experiment was carried out to verify the field performance of the collecting station for edible sunflower. The specific research contents and conclusions were as follows. First of all, experimental study on the physical characteristics of edible sunflower was made during harvest in Xinjiang. It mainly included the determination test of the basic physical quantity, the friction characteristic test and the impact seed falling test. The average moisture content of edible sunflower plate was 38.97% and that of culm was 65.49%. By the bevel method, we got the friction angle between the dish and the steel plate was about 29.2°, the static friction coefficient was 0.56. The experiments were carried out to obtain the operating parameters with less loss of sunflower plate, which provided the theoretical basis for the field operation of edible sunflower harvesting platform. Secondly, in this paper, the whole plan of the collecting station for edible sunflower was determined, and the structural design and parameter analysis of the key devices were carried out. This paper designed a kind of station for collecting edible sunflower by imitating the manual way of picking dish. The whole machine structure was mainly composed of the pick-up device, conveying device, collecting dish box, walking device, power transmission system and frame. By analyzing the segmented path map of manual picking-up and parabolic dish, and combining the working posture of the pick-up device in each harvesting stage, the bionic pick-up device was designed and the basic structural parameters were determined to achieve the goal of bionic dish taking action and the shortest parabolic dish path. The 3D model of the pick-up device was established and the kinematics analysis were carried out to obtain the displacement, speed and acceleration change rules of the pickup device's disk-bar and determined the best structure and working parameters combination of the pickup device. The conveying device was designed and the speed of it was calculated to be 92 r/min, the theoretical productivity was 2.19 t/h. By analyzing the power transmission system, we got the transmission law of chain. The field harvest test finally was carried out with the total harvest loss rate as the test index, the height of the plug plate, the rotational speed of the take-up rod and the forward speed of the unit as the test factors. The results showed that the collecting station for edible sunflower could complete the functions of picking up, transporting and collecting. The optimal combination of the collecting station for edible sunflower was that the height of the disc was 650 mm, the forward speed of the unit was 0.88 m/s, the rotational speed of the take-up rod was 23 r/min, and the total loss rate of harvest was less than 5%, which could meet the operation requirements of Xinjiang edible sunflower harvesting.