Design and test of automatic bag-feeding packaging machine of potatoes

Potato is the fourth largest grain crop in China, and China has become the country with the largest area under potato cultivation and the largest total output, so the demand for potato mechanisation operations is also increasing. Potato bagging is an important part of potato production, affecting the subsequent storage, transport and sale of potatoes. However, the current domestic potato bagging machines mainly rely on segmented manual operations and can not fully meet the large-scale bagging needs in recent years, such as poor bagging quality, low bagging efficiency, lack of automation and other issues, which seriously restricts the development of the potato industry. The study is based on the technology characteristics of plastic woven bags and the design ideas of integrating agricultural machinery, and thus an automatic woven bag packaging machine is designed. The bagging process, which integrates bag feeding, bag opening, bag lifting, bag covering and bagging, is adopted. And the structural design is mainly carried out from four aspects, namely, roller bag feeding device, opening-and-lifting bag device, clamping-and-filling bag device. Through roller bag feeding device, the forward conveying of the woven bag is completed. Under the action of the bag-opening device with suction cups, the openings on both sides of the woven bag are separated. With the help of the device for inserting and lifting the bag, the woven bags are lifted to the position below the hopper. Ultimately, with the help of the clamp bagging device, the potato drop process is completed. In addition, the bagging machine is equipped with a diffuse reflective photoelectric sensor to detect the forward position of the woven bag and a metal proximity switch sensor to detect the position of the bagging arm. PLC controls the action process of each mechanism, realizes the automatic bagging process of potatoes, and improves the potato bagging rate and bagging efficiency. Then, combined with the technical requirements of plastic woven bags, and according to the main structure and working principle of the bagging machine, the main parameters of the key components are determined, and the main factors affecting the bagging effect are clarified. With the upper roller pressure, suction cup adsorption height and adsorption time as test factors and the bag opening rate and bagging efficiency as evaluation indexes, a three-factor, three-level orthogonal experiment was carried out using the Box-Behnken neutral combination design function in Design-Expert. Variance analysis was also performed to analyze the impact of the interaction of various experimental factors on the evaluation indicators using the response surface method (RSM). According to the actual working conditions, the working parameters were optimised to determine the optimal values of each parameter. The test results show that when the pressure wheel pressure is 71.0 N, the suction cup adsorption height is 80.0 mm, and the suction cup adsorption time is 1.6 s, the bag opening rate of the woven bag is 98.36%, and the bagging efficiency is 68 bags/min. During the working process, the coordination relationship between the various parts of the bagging machine is stable, and the performance indexes meet the actual working requirements. The results of the study can provide a reference for the subsequent equipment research and development and optimization.