马铃薯组培苗气力引导式移植手设计与试验

Design and experiment on pneumatic guide transplanting hand for potato tissue culture seedlings

多手并行移植作业可有效提高接种效率,而现有组培苗接种移植手结构复杂、占用空间大,不适于狭小空间内多移植手并行接种作业,且对组培苗个体差异适应性较差,存在夹苗不稳或伤苗的情况,针对上述问题该文设计了一种负压引导式气力把持移植手,通过负压气流对马铃薯组培苗进行引导与把持,强化对组培苗个体差异的适应能力,实现组培苗的柔性容偏把持。该文对移植手吸嘴进行了三维建模及流体仿真分析,确定移植手吸嘴形式为外径5 mm、内径4 mm圆管状,前端设置90°夹角引导翅,引导翅顶点间距为10 mm。针对移植手引导性能进行正交试验,结果表明:对于平均苗径为(1.23±0.21)mm接种期马铃薯组培苗,当吸嘴真空度为8.6×10^(-3) MPa时,对组培苗容偏引导半径为4 mm。在移植手吸嘴真空度为8.6×10^(-3) MPa条件下进行茎段切割及扦插作业性能试验,结果表明:当利用厚度0.3 mm、直径45 mm圆盘切割刀以7 r/s以上转速切割茎段时,保证正常切割效果的进给速度可达0.03 m/s;对于直径为(0.7±0.1)、(1.1±0.1)、(1.5±0.1)mm条件下茎段,扦插速度为0.01 m/s时,茎段扦插成功率可达100%。该研究可为马铃薯组培苗自动移植设备开发提供技术参考。

Multi-hand parallel transplantation can effectively improve the efficiency of vaccination, but the majority of transplanting hands based on dimension-positioning are complex, which causes operation space of transplanting hand not enough when several transplanting hands are working at the same time. Meanwhile, the ability is poor for adapting individual differences of tissue culture seedlings, some tissue culture seedlings will be held unstably or be damaged by transplanting hand in the process of holding. Based on those issues, a tissue culture seedlings transplanting hand was designed in this research, which used a negative pressure air flow to complete the guidance and hold of potato tissue culture seedlings, to strengthen the adaptability for individual differences of tissue culture seedlings, to achieve flexible hold. The transplanting hand for tissue culture seedlings mainly consists of three parts, including the sucker, vacuum generating device, and negative pressure detection part. The sucker is the key part of transplanting hand, which decides the holding and guide effect of transplanting hand for tissue culture seedlings. In this paper, design and experiments were both mainly focused on the guide and control performance of sucker. The process that sucker holds a tissue culture seedling can be divided into three phases： guide and hold, stem section cutting, and stem section inserting. In guide and hold phase, the transplanting hand guide tissue culture seedlings of deviation from the holding position to mouth of sucker by negative pressure airflow. In stem section cutting phase and stem section inserting phase, transplantinged hands need to be stable to hold tissue culture seedlings, to ensure effect of stem section cutting and inserting. At the same time, sucker of transplanted hands should avoid tissue culture seedlings from damage. According to the above requirements of transplanting hand, first, the three-dimensional modeling was established based on work for sucker of transplanting hand and fluid simulation analysis was carried out based on Fluent software for shape of sucker of transplanting hand with guide wings. The shape of sucker of the transplanting hand was round tube with the outer diameter 5 mm, and inner diameter 4 mm, and the angle was set 90° for guide wings in the front of round tube, the distance was 10 mm between two guide wing vertex. In order to test the ability of accommodating tissue culture seedlings deviation by negative pressure air flow guide for transplanting hand, orthogonal experiment was carried out, the results showed that potato tissue culture seedlings of average diameter was 1.23 ± 0.21 mm, the radius of transplanting hand that guided tissue culture seedlings successfully was 4 mm when the vacuum of sucker was 8.6 × 10^-3 MPa. The process of vaccination should avoid the direction of transplanting hand movement and direction of tissue culture bending was vertical by adjusting three transplanting hand operation sequence in order to reduce the interference between the two. In order to test the hold performance of the transplanting hand, experiments of stem section cutting and stem section inserting were carried out under the condition of the vacuum of tube of 8.6× 10^-3 MPa, the results showed that the straight speed of cutter was 0.03 m/s when the rotate speed of cutter of thickness was 0.3 nun and diameter was 45 mm is 7 r/s. When stem diameter of stem section of tissue culture seedlings was （0.7 ± 0.1）, （1.1 ± 0.1）, （1.5 ±0.1） mm and the inserting speed was 0.01 m/s, the success rate of stem inserting was 100%.