手扶式水稻种绳直播机的设计研究

发布时间：2018-05-21 04:13

本文选题：种绳直播机 + 手扶式　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：针对牵引式种绳直播机不适合小地块作业,手推式种绳直播机利用人力、劳动强度大、作业效率低等问题,本文在前期研制的水稻种绳直播机样机的基础上,对原有的种绳直播机进行了试验研究,改变了原有样机的动力来源,并优化了关键部件的性能,设计了一种更适合小地块的实现旋耕、开沟、放种绳、覆土、镇压等一次完成的手扶式水稻种绳直播机,并对其进行了试验验证。主要研究成果如下。(1)设计了手扶式水稻种绳直播机。采用虚拟设计方法设计了手扶式水稻种绳直播机,该机主要由动力装置、旋耕兼行走装置、放绳系统、开沟装置、覆土和镇压装置等组成。选取了 YH6001型汽油微耕机作为手扶式水稻种绳直播机的动力装置,对原微耕机的旋耕刀耕刀进行了改装,改装后的微耕机耕宽由60cm增加到90cm,以适应种绳直播机的行距要求。该机的配套动力为5.2kw,作业行数为4行,幅宽为810mm,行间距为220mm。试验检测当旋耕深度平均值为10cm时,旋耕深度变异系数为0.0647,作业速度变异系数为0.0852,其工作性能能够满足手扶式水稻种绳直播机动力的要求。(2)试验研究了种绳的受力状态,建立了系统动力学模型,证明了种绳在工作过程中不会被拉断。因种绳的抗拉强度较低,在工作过程中容易被拉断,为此分别检测了两种作业速度下种绳的动态受力情况,分析得到了种绳的动态受力曲线,并建立了两种作业速度下种绳在0～1s时的受力数学模型。分析结果表明种绳的受力是一个典型的二阶振荡过程,种绳所受最大拉力为0.5N左右,1s以后系统趋于稳定,稳态值约为0.26N,不超过种绳的抗拉强度极限10N,证明了播种过程中种绳不会被拉断。(3)试验验证了所设计的种绳直播机的技术可行性。种绳直播的主要农业技术要求是开沟深度不能超过30mm,镇压后的覆土厚度应在10～20mm,覆土太厚影响种子发芽和出苗,若是种绳裸露于地表容易造成"干子"而不出苗。以水稻种绳直播机的开沟深度、开沟宽度和作业速度作为试验因素,以覆土厚度为评价指标进行了正交试验,探索了影响覆土厚度的因素。试验结果表明,对直播机覆土厚度影响最为显著的是开沟深度,开沟宽度、作业速度对覆土厚度也有一定的影响,当开沟深度为30mm、开沟宽度为35mm、作业速度为二档时,直播机的覆土效果最好。对研制的手扶式种绳直播机和原有的牵引式种绳直播机的主要性能指标做了田间对比试验,结果表明两者的开沟深度变异系数分别为0.052和0.061,覆土厚度变异系数分别为0.123和0.102,从试验数据和现场的作业效果来看,两者主要工作性能指标差别不大,所设计的手扶式水稻种绳直播机能够满足农业技术要求。
[Abstract]:Aiming at the problem that the traction seed rope direct seeding machine is not suitable for the small plot operation, the hand push seed rope direct seeding machine uses manpower, the labor intensity is large, the work efficiency is low, and so on, this paper is based on the prototype of the rice seed rope direct seeding machine, which was developed in the early stage. In this paper, the original seed rope direct seeding machine is tested, the power source of the original prototype is changed, and the performance of the key parts is optimized, and a more suitable rotary tillage, ditching, planting rope and soil covering is designed for small plots. A walking-type rice rope direct seeding machine was tested and verified. The main research results are as follows: 1) A hand-held rice seed rope direct seeding machine is designed. Using virtual design method, the hand-held rice seed rope direct seeding machine is designed. The machine is mainly composed of power device, rotary tillage and walking device, rope laying system, trench device, soil covering device and suppression device, etc. The YH6001 gasoline micro-tillage machine was selected as the power device of the walking type rice rope direct seeding machine. The rotary tillage knife of the original micro-tillage machine was modified. The tilling width of the modified micro-tillage machine was increased from 60cm to 90 cm to meet the requirements of the row spacing of the seeding rope direct seeding machine. The power of the machine is 5.2kw. the number of lines is 4, the width is 810mm and the distance between lines is 220mm. When the mean value of rotary tillage depth is 10cm, the coefficient of variation of rotary tillage depth is 0.0647, and the coefficient of variation of working speed is 0.0852. Its working performance can meet the power requirement of walking rice seed rope direct seeding machine. The system dynamics model is established, and it is proved that the rope will not be broken in the working process. Because of the low tensile strength of the rope, it is easy to be broken in the working process. Therefore, the dynamic force of the rope under two kinds of working speed is detected, and the dynamic stress curve of the rope is obtained. A mathematical model of the bearing force of the rope at 0 ~ 1 s at two operating speeds is established. The results show that the bearing force of the rope is a typical second-order oscillation process, and the system tends to be stable after the maximum tensile force of the rope is about 0.5 N / 1 s. The steady-state value is about 0.26N, which does not exceed the tensile strength limit of seed rope (10N), which proves that the seed rope will not be broken during seeding. The experiment verifies the technical feasibility of the designed seeding rope direct seeding machine. The main agricultural technique requirement of direct seeding is that the depth of trench should not be more than 30mm, the thickness of overlying soil should be 10 ~ 20mm, the thickness of covered soil will affect seed germination and seedling emergence, if the seed rope is exposed to the ground, it will cause "dry seed" and not seedling. Taking the depth, width and working speed of rice seed rope direct seeding machine as experimental factors, the orthogonal test was carried out with the thickness of overlying soil as the evaluation index, and the factors affecting the thickness of overlying soil were explored. The results show that the depth and width of gully, and the speed of operation have some influence on the thickness of overlying soil. When the depth of trench is 30mm, the width of trench is 35mm, and the speed of operation is second gear, the thickness of overlying soil is affected most obviously by the direct seeding machine. The seeding machine has the best effect on soil cover. The main performance indexes of the walking rope direct seeding machine and the original traction seed rope direct seeding machine were tested in the field. The results showed that the coefficient of variation of trench depth was 0.052 and 0.061, and the coefficient of variation of overlying soil thickness was 0.123 and 0.102, respectively. The designed walking rice seed rope direct seeding machine can meet the agricultural technical requirements.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.26

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