Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture

Nanjing, China

Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture

Nanjing, China
SEARCH FILTERS
Time filter
Source Type

Tian K.,Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture | Li X.,Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture | Shen C.,Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture | Zhang B.,Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2017

Cutting blade is one of the key parts of a cannabis harvester and the cutting performance of the blade directly determines the performance of the machine. Due to the current lack of special cutting blades for existing cannabis harvesters, rice and wheat harvester cutting blades have to be utilized instead. However, these cutting blades have problems associated with large cutting resistance, high energy consumption, and poor cutting quality. For these reasons, this study aimed to utilize the principle of bionics to develop a longicorn mouthparts palate for a bionic prototype. This was achieved by extracting the cutting tooth profile curve of longicorn mouthparts palate, instead of the ordinary rice and wheat harvester blade triangular tines, and thus designing the bionic cutting blade. Using a double-action blades testing system, which was composed of a self-developed double-action blades cutting device and a WDW-10 computer-controlled electronic universal testing machine, a single stalk cutting performance contrast test was carried out using the cannabis stalks of harvest time. Comparing the 2 types of blades' cutting force -displacement curves can be seen that both of the curves could be divided into extrusion, cutting, and cutting out stages. In extrusion stage, due to the large pitch and sharp teeth of the bionic blade, the unit area of cannabis stalk suffered great stress, consequently strengthening the cutting ability of the bionic blade. While the teeth of ordinary blades were arranged closer, achieving the same cutting driving force, the unit area of cannabis stalk suffered less stress, thus, the blade showed more effect of compression on the stalk. In cutting stage, due to the unique arc tooth and tooth back groove structure of the bionic blade, the teeth edge mainly played a role of sliding cut, which can greatly reducing the cutting resistance during cutting. Secondly, the adjacent protrusions of the arc tooth boundary formed a wedge block structure, which resulted in the effect of splitting the transverse xylem instantly. In addition, the back groove of tooth played a role of accommodating the shred wooden material, which can also reduce the resistance of cutting. While, due to the close arrangement of the triangular teeth of ordinary blade, the sliding cut effect was poor and they had no capacity to accommodate the shred material. When cutting, the structure suffered from a blocking effect instead, which resulted in an increase of cutting resistance. In cutting out state, due to the bionic blade can cut more thoroughly, less uncut bark fiber and wood debris entered the two opposite blades, thus keeping the friction small, and the bionic blade force is closer to no-load driving force. Comparison of cutting stubbles of two types of blades can be seen that the stubbes cut by bionic blades is more flush than that by ordinary blades. The statistical average of both groups of test data showed that the single stalk maximum cutting force and the cutting energy consumption of bionic blade and ordinary blade were 442.6, 478.1 N and 2.16, 2.35 J, respectively. In comparison to an ordinary blade, the bionic blade achieved a reduction of the average maximum cutting force and cutting energy consumption by 7.4% and 8.0%, respectively. This showed that the bionic blade has a better performance of drag reduction and consumption reduction than the ordinary blade. The maximum cutting force of different blades was verified via F test, resulting in an F value of 15.49 at a significance level of P<0.01, which reveals that the blade type has a significant influence on the cutting force. Furthermore, the cutting energy consumption of different blades was also verified via F test, resulting in an F value of 5.735 at a significance level of P<0.05, which reveals that the blade type also has a significant influence on the cutting energy consumption of a single stalk. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

Loading Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture collaborators
Loading Nanjing Research Institute for Agricultural Mechanization of Ministry of Agriculture collaborators