氣吸式精量播種機主要特點及工作原理

由于(yu)氣吸式(shi)精量(liang)播種(zhong)(zhong)(zhong)機(ji)(ji)投種(zhong)(zhong)(zhong)點低、種(zhong)(zhong)(zhong)床平(ping)整(zheng)、籽粒分布均(jun)(jun)勻、種(zhong)(zhong)(zhong)深一(yi)致以及出苗整(zheng)齊(qi)等符合農(nong)藝(yi)要(yao)求的特點，越來越受到農(nong)工們(men)的歡迎。在(zai)該機(ji)(ji)氣吸體上更換不同(tong)的排(pai)種(zhong)(zhong)(zhong)盤和(he)采用不同(tong)的傳(chuan)動比，即(ji)可精量(liang)播種(zhong)(zhong)(zhong)棉花、玉米、油(you)葵以及甜菜等多種(zhong)(zhong)(zhong)作(zuo)物。氣吸式(shi)播種(zhong)(zhong)(zhong)機(ji)(ji)可膜(mo)上、膜(mo)下點播，株、行距可調，通用性(xing)強，并能(neng)一(yi)次(ci)完成(cheng)鋪膜(mo)、施(shi)肥、開溝、播種(zhong)(zhong)(zhong)、覆土和(he)鎮壓(ya)作(zuo)業，是滿足棉花、玉米、油(you)葵耕作(zuo)模式(shi)中(zhong)實(shi)現均(jun)(jun)衡增產的更新(xin)機(ji)(ji)械。這種(zhong)(zhong)(zhong)播種(zhong)(zhong)(zhong)機(ji)(ji)雖(sui)然有其(qi)明顯的優越性(xing)，但(dan)也存在(zai)不足之(zhi)處，需要(yao)使用者不斷總結經驗，發揮其(qi)長處，彌補其(qi)不足。

了解工作原理是用好氣吸式精量播種機的保證。

氣吸式播(bo)種(zhong)(zhong)器(qi)工作(zuo)時由高速風機產生負(fu)壓(ya)，傳給排種(zhong)(zhong)單體(ti)的真空(kong)(kong)(kong)(kong)室(shi)。排種(zhong)(zhong)盤回轉時，在(zai)真空(kong)(kong)(kong)(kong)室(shi)負(fu)壓(ya)作(zuo)用下吸附種(zhong)(zhong)子(zi)，并隨排種(zhong)(zhong)盤一(yi)起轉動(dong)。當種(zhong)(zhong)子(zi)轉出真空(kong)(kong)(kong)(kong)室(shi)后，不再承受負(fu)壓(ya)，就(jiu)靠(kao)自重或在(zai)刮種(zhong)(zhong)器(qi)作(zuo)用下落(luo)在(zai)溝內。其工作(zuo)質(zhi)量(liang)可以用空(kong)(kong)(kong)(kong)穴率、重播(bo)率來(lai)評價(jia)。主要影(ying)響因素(su)有真空(kong)(kong)(kong)(kong)度、吸孔形狀(zhuang)、種(zhong)(zhong)子(zi)尺(chi)寸以及(ji)刮種(zhong)(zhong)器(qi)的構(gou)造和(he)調整等(deng)。

（1）真空度。真空度越(yue)大則吸附種子的(de)能力越(yue)強，越(yue)不易產生空穴；但單個吸孔吸附幾粒(li)種子的(de)可能性加大，使(shi)重播率(lv)增大。

（2）吸孔直徑。吸(xi)(xi)孔越大，吸(xi)(xi)孔處對種子的吸(xi)(xi)力越大，同樣(yang)可使空穴率減少、重(zhong)播率增加。

（3）刮種器。它的作用是刮去吸(xi)孔吸(xi)附的多余種(zhong)(zhong)子，降低重播率。在(zai)工(gong)作中(zhong)由于(yu)機具(ju)的裝配(pei)質量不好(hao)或運動中(zhong)碰撞，使(shi)刮種(zhong)(zhong)器(qi)(qi)與(yu)排(pai)種(zhong)(zhong)盤(pan)(pan)之(zhi)間(jian)的距(ju)離(li)產(chan)生變化，或導致碎種(zhong)(zhong)，或達(da)不到刮種(zhong)(zhong)的目(mu)的。刮種(zhong)(zhong)器(qi)(qi)與(yu)排(pai)種(zhong)(zhong)盤(pan)(pan)之(zhi)間(jian)的距(ju)離(li)應在(zai)0與(yu)種(zhong)(zhong)子平均直(zhi)徑的一半之(zhi)間(jian)，使(shi)種(zhong)(zhong)子無法進入刮種(zhong)(zhong)器(qi)(qi)與(yu)排(pai)種(zhong)(zhong)盤(pan)(pan)之(zhi)間(jian)形成的間(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。