油菜毯状苗移栽机开沟镇压部件设计与参数优化

针对插秧机底盘空间受限、配重低等问题,借鉴插秧机切块栽插原理,增设开沟、覆土镇压功能,设计驱动型波纹圆盘开沟与镇压部件,形成适宜稻板田移栽的油菜毯状苗移栽机。在确定圆盘结构参数的基础上对圆盘运动轨迹进行了分析,建立了机具前进速度、开沟深度和圆盘转速等主要参数的匹配关系,在机具最大前进速度1.5 m/s时解得圆盘转速为115 r/min。为确定镇压轮最佳设计参数组合进行了田间试验,通过对机具前进速度、轮盘夹角、单轮倾角和开距,采用响应面试验分析方法建立主要影响因素与考察指标之间的回归数学模型,确定最佳参数组合:机具前进速度0.95 m/s,轮盘夹角为19°,单轮倾角为45.8°,开距为64.1 mm,测得秧苗直立度合格率为86.66%和离土力为3.31 N,与理论值绝对误差分别为0.69%和3.50%。该研究可为毯状苗切块栽插旱地移栽机设计提供参考。

Design and parameter optimization of ditching and compacting parts of rapeseed carpet seedling transplanter

Abstract: Nowadays, rapeseed has been considered as the most important oil crop in China, and the rapeseed seedling transplantation has become a main cultivation pattern in the crop rotation of rice and rapeseed. The existing transplanter is still with low working efficiency and not suitable for paddy soil, which has poor fluidity of soil. In aiming of solving these problems, a fully automatic cultivation pattern was proposed, which cut and picked seedling blocks with high speed and then transplanted them under the condition of sticky heavy soil. By using the slicing and transplanting principle of rice transplanter, the functions of ditching, covering and compacting the soil were set up, and finally a rapeseed seedling carpet transplanter was formed, which was suitable for the transplantation in paddy stubble field instead of being limited in paddy field. In view of the original machine''s drawbacks such as little installation space of underframe and light counterbalance weight, the paper described a design of a driven ditching device with oblique ripple and a V-shaped press wheel.In the process of observing the power, the design skillfully use the origin fan pulley on the engine of the transplanter chassis to drive the hydraulic pump. In aim of realizing a continuous adjustment of the running speed and ripple disc coulter of the machine to meet the requirement of different soil conditions, a series of hydraulic valve has been put into use. The designed machine could adapt to different soil condition. By analyzing the characteristics of transplanter and the requirements for transplanting the rapeseed blanket seedlings, the paper accomplished the calculation of the diameter and width of wave coulter. The paper carried out an analysis on motion trail based on the determination of disc parameter, and established the association of principal parameters such as forward speed, depth of ditching and rotation speed of wave coulter. The conclusion was drawn that when the maximum forward speed reached 1.5 m/s, the rotation speed of disc was 115 r/min. In order to confirm the optimum design parameters of press wheel, we performed the field experiment. The response surface design (RSD) was applied to establish a mathematical regression model between main influence factors and inspection targets by analyzing the forward speed, press wheel angle, undercut angle of one wheel and distance between centers, and finally the optimal data were obtained as follows: the forward speed was 0.95 m/s, the angle of press wheel was 19o, the undercut angle of one wheel was 45.8o and the distance between centers was 64 mm. The optimized structure design and operating parameters were both able to achieve the requirements for transplanting the rapeseed blanket seedlings. As a summary, the research establishes a theoretical basis for the rapeseed carpet seedlings transplanting under the condition of sticky heavy soil, and offers a reference for designing this type of transplanter. At the same time, it also has an important significance to solve the technical bottleneck problem of rapeseed transplanting mechanization.