摘要
【目的】我国树苗栽植机械化水平相对较低,扶苗机构为树苗移栽机植苗系统中的关键机构之一。研发针对我国杨树苗移栽机的齿轮齿条式扶苗机构,可以保证树苗移栽设备的栽植效果。【方法】首先针对长杆式树苗移栽作业,分析速生杨树苗的物理特性,得到树苗的长度、地径变化范围数据,提出一种齿轮齿条式扶苗机构的设计方案,分析齿轮齿条式扶苗机构栽植性能与运动参数的关系,计算其扶苗支撑架的初始位置以及确定扶苗工作行程,利用接触碰撞算法计算齿轮齿条啮合的约束条件和运动参数。使用ADAMS仿真软件建立扶苗机构多刚度接触动力学模型并进行仿真,探究齿轮齿条模数对扶苗效果的影响,通过扶苗支撑架质心的位移和速度变化曲线分析扶苗运动的准确性,通过传动齿轮转速变化和齿轮齿条啮合力变化验证扶苗机构结构的传动性能。【结果】齿轮齿条模数为9,扶苗效果最佳,此时扶苗支撑架质心在前进方向上的速度波动较小,并且位移变化稳定,位移和时间量近似于线性关系,扶苗过程接近匀速运动,速度为122 mm/s左右;扶苗运动单次工作行程达到599.9 mm,满足了实际需要大于568.4 mm的设计要求;扶苗机构各级齿轮动力传递稳定,齿面最大接触力为512.6 N,远小于材料强度,没有发生跳跃情况和阻滞情况。【结论】齿轮齿条式扶苗机构可以满足杨树苗栽植的扶苗运动要求,实现零速移栽,保证了树苗栽植直立度,并且有效改善了以往树苗栽植过程中的扶苗方式,具有良好的运动稳定性,安全高效。本研究对造林机械设备具有一定的指导作用。
[Objective] The mechanization level of seedling planting in China is relatively low. The seedling supporting mechanism is one of the key institutions in the seedling planting system of the seedling transplanter. The rack and pinion seedling supporting mechanism for the poplar seedling transplanter in China is developed to ensure the planting effect of the seedling transplanting equipment. [Method] Firstly,aiming at the transplanting operation of long rod seedlings, the physical characteristics of fast-growing poplar seedlings were analyzed, the variation range data of seedling length and ground diameter were obtained, a design scheme of rack and pinion seedling supporting mechanism was proposed, the relationship between planting performance and motion parameters of rack and pinion seedling supporting mechanism was analyzed, the initial position of seedling supporting frame was calculated, and the working stroke of seedling supporting was determined. The contact collision algorithm was used to calculate the meshing constraints and motion parameters of gear and rack. We used ADAMS simulation software to establish and simulate the multi stiffness contact dynamic model of the seedling supporting mechanism, explore the influence of the gear rack modulus on the seedling supporting effect, analyze the accuracy of the seedling supporting movement through the displacement and speed change curve of the mass center of the seedling supporting frame, and verify the transmission performance of the seedling supporting mechanism structure through the change of transmission gear speed and the change of gear rack meshing force. [Result] The module of gear and rack was 9, and the seedling raising effect was the best. At this time, the speed fluctuation of the center of mass of the seedling raising support frame in the forward direction was small, and the displacement change was stable. The displacement and time were approximately linear. The seedling raising process was close to uniform motion, and the speed was about 122 mm/s. The
作者
刘九庆
桂康
杨春梅
Liu Jiuqing;Gui Kang;Yang Chunmei(School of Mechanical and Electrical Engineering,National Forestry Grassland Artificial Intelligence and Equipment Engineering Technology Research Center,Northeast Forestry University,Harbin 150040,Heilongjiang,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2022年第6期146-155,共10页
Journal of Beijing Forestry University
基金
黑龙江省自然科学基金项目(TD2020C001)。
关键词
树苗移栽机
齿轮齿条式
扶苗机构
动力学仿真
seedling transplanter
rack and pinion type
seedling supporting institutions
dynamics simulation
