氣吸式精量播種機主要特點及工作原理

由于氣(qi)吸式(shi)精(jing)量(liang)播(bo)種(zhong)(zhong)機(ji)投種(zhong)(zhong)點低、種(zhong)(zhong)床(chuang)平整(zheng)、籽粒分布均(jun)勻、種(zhong)(zhong)深一(yi)致以(yi)及(ji)出苗整(zheng)齊等符合農藝要(yao)求的(de)(de)(de)特點，越(yue)來越(yue)受到農工們(men)的(de)(de)(de)歡迎。在該機(ji)氣(qi)吸體上(shang)更換(huan)不(bu)同(tong)的(de)(de)(de)排種(zhong)(zhong)盤和(he)采用(yong)不(bu)同(tong)的(de)(de)(de)傳動比(bi)，即可(ke)精(jing)量(liang)播(bo)種(zhong)(zhong)棉花、玉米(mi)、油(you)葵以(yi)及(ji)甜菜等多種(zhong)(zhong)作物。氣(qi)吸式(shi)播(bo)種(zhong)(zhong)機(ji)可(ke)膜上(shang)、膜下(xia)點播(bo)，株、行(xing)距可(ke)調，通用(yong)性強，并能一(yi)次完(wan)成鋪膜、施肥、開溝、播(bo)種(zhong)(zhong)、覆土和(he)鎮(zhen)壓作業，是滿足棉花、玉米(mi)、油(you)葵耕作模式(shi)中(zhong)實(shi)現均(jun)衡(heng)增產的(de)(de)(de)更新機(ji)械。這種(zhong)(zhong)播(bo)種(zhong)(zhong)機(ji)雖然有其(qi)(qi)明顯(xian)的(de)(de)(de)優越(yue)性，但也存在不(bu)足之處(chu)，需要(yao)使用(yong)者不(bu)斷總結經驗，發揮其(qi)(qi)長處(chu)，彌補(bu)其(qi)(qi)不(bu)足。

了解工作原理是用好氣吸式精量播種機的保證。

氣吸(xi)(xi)式播種(zhong)(zhong)器工作時由高速風機產生負(fu)壓(ya)，傳(chuan)給排種(zhong)(zhong)單體的(de)真(zhen)空室。排種(zhong)(zhong)盤回轉(zhuan)時，在真(zhen)空室負(fu)壓(ya)作用(yong)下吸(xi)(xi)附種(zhong)(zhong)子(zi)(zi)，并隨排種(zhong)(zhong)盤一起轉(zhuan)動。當種(zhong)(zhong)子(zi)(zi)轉(zhuan)出(chu)真(zhen)空室后，不再(zai)承(cheng)受(shou)負(fu)壓(ya)，就靠自重(zhong)或在刮種(zhong)(zhong)器作用(yong)下落(luo)在溝(gou)內。其(qi)工作質量(liang)可以用(yong)空穴率(lv)、重(zhong)播率(lv)來(lai)評價。主要影響因素有真(zhen)空度、吸(xi)(xi)孔形(xing)狀、種(zhong)(zhong)子(zi)(zi)尺寸以及刮種(zhong)(zhong)器的(de)構造和(he)調整(zheng)等。

（1）真空度。真空度越(yue)大則吸附種子的能(neng)力越(yue)強，越(yue)不易產生空穴；但單(dan)個(ge)吸孔吸附幾粒種子的可能(neng)性加(jia)大，使重播率(lv)增(zeng)大。

（2）吸孔直徑。吸孔越(yue)大，吸孔處對種子(zi)的吸力越(yue)大，同樣可使空穴率(lv)減少、重播率(lv)增加。

（3）刮種器。它的作用是(shi)刮(gua)去吸孔(kong)吸附(fu)的多余種(zhong)(zhong)(zhong)(zhong)子(zi)(zi)，降低重播率(lv)。在工作中由(you)于機具的裝配質量不(bu)好或(huo)(huo)運動中碰撞，使刮(gua)種(zhong)(zhong)(zhong)(zhong)器(qi)與(yu)排(pai)種(zhong)(zhong)(zhong)(zhong)盤之(zhi)(zhi)間(jian)的距離產生變化(hua)，或(huo)(huo)導致碎種(zhong)(zhong)(zhong)(zhong)，或(huo)(huo)達不(bu)到刮(gua)種(zhong)(zhong)(zhong)(zhong)的目的。刮(gua)種(zhong)(zhong)(zhong)(zhong)器(qi)與(yu)排(pai)種(zhong)(zhong)(zhong)(zhong)盤之(zhi)(zhi)間(jian)的距離應在0與(yu)種(zhong)(zhong)(zhong)(zhong)子(zi)(zi)平均(jun)直徑的一半之(zhi)(zhi)間(jian)，使種(zhong)(zhong)(zhong)(zhong)子(zi)(zi)無法(fa)進入刮(gua)種(zhong)(zhong)(zhong)(zhong)器(qi)與(yu)排(pai)種(zhong)(zhong)(zhong)(zhong)盤之(zhi)(zhi)間(jian)形成(cheng)的間(jian)隙。

（4）風機。它是產生負壓以供排種器吸附種子的關鍵部件，風機葉輪要高速旋轉以產生高的負壓。風機風力小、風管漏氣或風管直徑小均會產生排種器真空室真空度小、吸不上種子而產生漏播現象。