Experiments On Precision Meter-device For Tabacco

Tabacco is an important cash crop in china. At present, tabacco crop farming mainly produced by individual organize, and taking handwork or self-mechanize as chief sowing style. It is characterized by poor scalization, poor mechanize, dispersive and the weak ability of self-development. The mechanical tabacco seeder now available exists shortage of seed squander profusely, as well as high damage rate. While, air-aspiration type tabacco seeder exists shortage of low produce efficiency and the hole block up easily, they are both can’t widely accepted by tabacco grower, so, tabacco seeder that can be applied in practice is relatively few. In order to research precise meter for tabacco that can be accepted by tabacco grower, several typical pneumatic meterings in domestic at current were analyzed from the aspects of theory and structure. The tabacco meter structure was optimized aim to solve landing precision and poor gas tightness problem on the basis of pneumatic precision seeder for small size seeds in this paper. The mainly conclusions are got in this paper as following:(1) The structure of sowing device was optimized on the basis of dynamic analysis on working process. In contrast with the previous results, new roller-type precision meter device would be a surer guarantee for sowing quality; Compared with sowing device designed by Wang Xi-qiang, blowing device and the way of air admission were improved; Compared with sowing device designed by Liu Jian-feng, blowing direction and sub-atmospheric pressure and barotropy chambers compound mode have changed; Compared with sowing device for vegetables designed by Chen Jia-qi, device structure is simplified,and air-tightness is increased.(2) The pressure and velocity analog simulation of blowing device results show:the design of device is reasonable, it ensures velocity and pressure of airflows well-distributed, thus, spacing in rows would be guaranteed.(3) Variance analysis of orthogonal regression test indicates that rotation, adsorption pressure, vibration frequency is the main factors affecting pass rate, iterate rate, omit rate; the mathematical model between various factors and evaluation index can be obtained from regression analysis result; the optimal parameter combination is roller speed is650r/h, adsorption pressure is0.95KPa, vibration frequency is100Hz, the pass rate85.99%, the iterate rate6.9%, the omit rate7.7%.(4) Single factor high speed video test of seed dropping trace is carried out, the result shows that landing location plays an significant role in seed moving trace, landing on the wall has more changeable bounce direction as well as great rebound force compared with landing on bottom; the greater rotation speed, blow pressure, dropping height, the more energy seed can get, then,bounce would be more obvious; landing location reflects that transport velocity is an important experimental factor for sowing effects.