Study On Floating Corn Single Panicle Threshing Device

Corn is an important food crop in China.Corn threshing is a key link in maize harvest.The performance of corn thresher directly affects the threshing efficiency and quality of corn.At present,seed corn thresher has high damage rate.Because of the difference in diameter of corn ear,the non automatic adjustment of threshing gap of corn threshing machine is one of the important causes of corn threshing damage.In order to reduce the mechanical damage in the threshing process of seed corn,realize the automatic regulation of threshing clearance and threshing without cob fracture,this paper first studied the compression characteristics of the corn ear and optimized the threshing parts.On this basis,the floating corn single panicle threshing device was designed,and the related experimental research was carried out.The main contents are as follows:1.In order to study the anti-pressing properties and rupture laws of corn ear and explore the effect of water content on anti-pressing properties,the static compress experiments of corn ears were carried out on the DNS series electronic universal testing machine.By analyzing the effect of corn cob water content on the compressive capacity of corn ears,the water content of corn cob which was most suitable for the corn threshing without cob fracture and the compressive peak force were obtained.The internal and external changes of corn ear rupture process were analyzed,and the mechanism of corn ear rupture was obtained.The research results provided a reference for the design of corn threshing device without cob fracture.2.In order to further optimize the threshing part,the arrangement angle of the discrete unit and the threshing unit was analyzed and designed.Through the comparison test of the threshing performance of two kinds of arrangement angles and the analysis of high speed photography,the influence mechanism of the arrangement angle of the discrete unit and the threshing unit on the corn threshing performance was studied and the better arrangement angle was obtained.At the same time,the problems and shortcomings of corn ear multi roller threshing device were found out,which provided ideas for the design of the new threshing device.3.In order to realize automatic adjustment of threshing clearance and solve the problems found in the experiment,the floating corn single panicle threshing device was designed.The device was composed of the main components such as clearance adjustment device,feeding hopper,discrete roller,threshing roller and differential roller.4.Through the single factor test and regression orthogonal rotation combination test of the floating corn single panicle threshing device,the effects of grain moisture content,discrete roll speed,rotational speed of threshing roll and speed of differential roll on the damage rate and non removal rate of corn grain were analyzed,and the optimum working parameters combination of threshing device was obtained.The actual threshing performance of threshing device was obtained through verifying test.The floating corn single panicle threshing device has the characteristics of low grain damage rate,high net removal rate,continuous core,miniaturization and strong adaptability.This study further improves the threshing mechanism of corn seed,and further improves threshing technology and threshing performance.