Study On The Key Parts Of Shallow-tiller And Its Force-testing System Based On Virtual Instruments

As a part of the Sino-Australian project 揂CIAR 961143 Sustainable Mechanized Dry-land Grain Production? this thesis is to study effects of shallow-tillage further. Firstly, how the shallow-shovel抯 structure parameters, such as its working width B, its wing width b, its thickness ? its wingspan angel a its cutting angel 1 and its clearance angel & influence its tractive resistance of shallow-shovel is studied. According to the results, a new kind of shallow-shovel with narrow wing is designed, the tractive resistance of which is about 1 7.27~-2 1.76% less than the old one. A force-testing system based on virtual instruments is developed to automate the acquisition, processing and analysis of data. By using the force-testing system, the dynamic and random tractive resistance of the shallow-shovel is investigated; the average of the tractive resistance is calculated, and the normality of the tractive resistance is verified; the power spectrum of the tractive resistance is analyzed as well. The results show that the tractive resistance signals of the shallow-shovel fit to normal distribution and the tractive resistance of the short-wing furrow opener is reduced about 44.12% after shallow-tillage in no-tillage fields without residue. The effects of shallow-tillage are studied. The results show that shallow-tillage kills grasses remarkably, improves soil-surface obviously, increases the soil temperature effectively, decreases the surface soil bulk density and the tractive resistance of an opener notably, while it has little effects on residue cover and soil moisture content.