双鸭嘴式大蒜正头装置调头机理分析与试验

Mechanism Analysis and Test of Adjusting Garlics Upwards Using Two Duckbill Devices

针对当前大蒜机械化播种鳞芽正头率较低的问题,测定了苍山大蒜的物理属性参数及几何参数,采用离散元技术,建立双鸭嘴式大蒜正头机构播种动力学模型;仿真研究了蒜种在3种正头机构中的运动规律,分析了不同接种鸭嘴曲线形状、蒜种重心、插播转速及蒜种二次弹跳对正头率的影响规律,明确了蒜种正头机理。试制了室内播种试验台及大田样机,开展了播种试验,采用可视化方法提取了试验过程中蒜种运动动态图像,结果与仿真过程基本一致,试验正头率与仿真正头率的误差在5%以内,表明采用离散元法对播种过程中蒜种的运动规律进行分析是可行的;田间试验蒜种正头率最高可达95. 67%,提高了4. 67个百分点。

Due to the problem of low rate of garlic bulbil with upward direction after mechanical sowing in China recently,the physical and geometric parameters of Cangshan garlic were measured,and the discrete element method was used.The dynamics model of mechanism with double duck bill shape adjusting the direction of the garlic bulbil was established.The movement law of garlic in three kinds of garlic adjusting mechanism and different factors’influences on the rate of garlic bulbil with upward direction were studied,such as the different curves of duck bill,gravity of garlics,speed of seeding and the secondary bouncing of garlics.Besides,the principle of adjusting the garlics to upward direction was also studied.The indoor planting test-bed and the field prototype were manufactured.The seeding experiment was carried out,and the dynamic images of garlics’movement at one point were recorded by visual method.It was found that the result was consistent with the simulation process,and the deviation between the rate of garlic bulbil with upward direction of the experiment and that of the simulation was less than 5%.The results showed that it was effective to use the discrete element method to analyze the movement of garlics during sowing.The rate of garlic bulbil with upward direction of the test in field can be up to 95.67%,which was increased by 4.67 percentage points.