【作者】 吕钊钦；

【导师】 余松烈； 李汝莘；

【作者基本信息】 山东农业大学 ， 作物栽培学与耕作学， 2005， 博士

【摘要】 冬小麦机械断根技术源于小麦高产的生产实践,是小麦精播高产栽培的一项重要配套技术。山东农业大学余松烈院士等对小麦断根研究发现:深耘断根对植株生长有促控作用,不仅有断老根、喷新根、深扎根,促进小麦根系发育,扩大根系在土壤中的分布范围,提高根系活力,还具有控制分蘖和群体、提高成穗率,促进穗大粒多和防早衰、促粒重的作用,增产效果十分显著。研制开发适合小麦断根要求的新型断根机械,是大面积推广小麦断根新技术,促进断根增产、增效的必要条件,是实现小麦断根机械化的关键技术,也是发展小麦全过程机械化的关键环节。本课题以小麦断根增产理论为基础,采用农机农艺相结合的方法,研究设计了适合小麦断根要求的工作部件及其合理配置方案,进行了多功能小麦断根机的结构设计,在动力学分析的基础上,对其工作稳定性、操纵性能、断根质量和断根效果进行了全面、系统地研究。在国内,首次设计完成了多功能小麦断根机械,解决了小麦断根机械化作业的关键技术。选题在理论上先进、生产上具有重要的推广价值和实际意义。1.根据小麦断根的农艺要求,研究设计了断根机的总体结构,利用现代设计理论,对齿轮传动、链传动、三角带传动及轴承进行了可靠性设计。(1)首次设计断根铲和断根刀两种工作部件,且能够方便地进行多种组合配置,断根行间距可在10～50cm之间调整。(2)首次设计弹性限深仿形轮机构,仿形轮在仿形弹簧的作用下随地表起伏运动,以保证断根深度的稳定;断根深度可在5～25cm 间调整。(3)设计弹性镇压轮装置,镇压力的大小可通过镇压弹簧来调节,保证断根后土壤的压实,以利于保墒。更多还原

【Abstract】 The technique of winter wheat mechanical root cutting came from high-yield producing practice, and it’s an important compounding technique for winter wheat precision planting. CAE academician Yu Songlie and other scholars, who are from SDAU, found that deep cultivation not only cut original fibers, accelerated new roots to grow deeply and widely, but also increased the rate of effective tillers, accelerated spike to grow bigger, accelerated kernels of each spike to be more, prevented premature senility, and it did have a remarkable increase-yield effect. It is a requirement for popularizing root-cutting technique to study and empolder new model of root-cutting machine, it is a key to develop wheat root-cutting production mechanization as well. This thesis based on wheat root-cutting theory, took use of the method of combining farming machinery with agriculture theory, finished the design of multifunctional wheat root-cutting machine for the first time at home. Based on the dynamic analysis to the machine, studied the operating stability, handling capability, root-cutting quality and effect completely and systemically, which solved the key technique to wheat root-cutting mechanization. 1. According to the agriculture request of wheat root-cutting technique, the main structure of the wheat root-cutting machine was designed and studied. The main structure characteristics and innovation points as follows: 1) Adopted root-cutting shovels and blades as operating parts for the first time. In order to fit different wheat planting models, different assembled configuration with root-cutting shovels and knives were designed, and the root-cutting distance between two near rows can adjust at a range of 100~500mm freely. 2) Designed a flexibility depth-control and profile-modeling wheel framework creatively, the profile-modeling wheel follows the surface of the earth under the press of profile-modeling spring, ensuring a steady root-cutting depth. The root-cutting depth can adjust at the range of 50~250mm freely. 3) Designed the flexibility-squash wheel framework to squash the soil after cutting roots, the squash force can be adjusted by changing the working length of the spring. 4) Designed triangle tooth-shape surfaces between root-cutting shovel and machine frame, which ensured the enter-soil angle keep steady in work. 5) Adopted two sets of driving wheels: rubber wheel and iron wheel, the tread(distance between the two driving wheels) can freely adjust at a range of 350-800mm. 6) Designed a ±120°-free-turning joint for driving wheel and axle connected, keeping the root-cutting machine to turn and handle flexibly. 7) Designed the type-new clutch that assembled with texrope pulley together, which characteristically by small size, compacted structure, steadily transmission of power and a longer longevity. 8) Used the texrope transmission, chain and gear to transmit the power, which had a simple structure and lower cost. 2. Studied and designed the key root-cutting parts—root-cutting shovel and root-cutting blade for the first time. The root-cutting shovel’s parameters have an important effect on root-cutting quality. Through analyzing the structural parameters, for the first time proposed three main root-cutting mechanisms, and tested the root-cutting quality and effect with different parameters, finally got the best structural parameters. The test shows: the root-cutting power of a shovel mainly lies on soil-cutting angle β0, the sharp degree of blade and wing-open angle 2γ. Smash-soil angle βhas an assistant effect for wheat cutting root. With the increase of the wing-open angle and the soil-smash angle, the quantity of roots being cut increased continuously, but soil turnover, wheat seedlings injured and irregular earth surface will be serious. The bigger entering soil angle αis, the more both quantity of roots being cut and wheat seedling injured are, while α=3~10°, there is no soil turnover and wheat seedlings injured. The soil deformation area, root-cutting quantity and wheat seedings injured increased while the root-cutting shovel’s breadth B and root-cutting depth increased. The test shows that the reasonable root-cutting shovel parameters are: γ=45°, β=12°, β0 =18°, α=8.5°, B=8cm. The root-cutting blade is a new-type wheat root-cutting operation part, its figure character can express by 4 sizes: curve radius r, height H, the length to protrude L, blade’s handle crosssection d×C. The distance between root-cutting knife and wheat seedling, s , androot-cutting depth, h , are two important factors which effect on the root-cutting quality. The test shows that the reasonable configuration parameters of root-cutting blade are: h=120~150mm, s=30~50mm 3. Researched entirely working stability and handling capability of the wheat root-cutting machine, which ensured the design quality. Through analysing the dynamics of the wheat root-cutting machine and soil mechanics, the mass requirement and the centroid requirement of wheat root-cutting machine going forward steady and keeping the root-cutting depth steady were given in theory, as well the computational formulas were given, which provided a new theoretical basis to design the machine. The theoretical analysis and tests showed that the mass of the machine at the range of 60~125kg, and the centroid location is 15~40mm in front of driving shaft. The moving velocity is another important factor that influences the working stability and handling capability of the machine. The test showed that the woking stability decreased while over speeding, meanwhile deteriorated the handling capability, injured a great deal of wheat seedling ; but lower productivity with lower speed. The proper moving velocity is about 2.8~3.0km/h. 4. Studied entirely root-cutting quality and effect with different models of root-cutting parts assembled, and got the perfect root-cutting compages. The compages of working parts is an important factor that influences the root-cutting quality and effect. According to the requirement of agriculture, three different root-cutting testing projects were designed: cutting root with shovels compages, cutting root with blades compages, cutting root with both shovels and blades compages. The results showed that: all three projects have remarkable root-cutting and product-increase effect. Generally speaking, the rate of root-cutting of shovels compages is 25.8%, the rate of root-cutting of blades compages is 31.6%, the rate of root-cutting of shovels & blades is 42.1%; the average soil bulk weight decrease by 3.81~6.5%, and the average soil moisture content increase by 0.3~0.7% because of improving the soil surface condation. The root-cutting operation have an effect of restrain first and promote later, after jointing the roots weight evidently beyond the contrast which did not cut roots, and the deeper roots is also more. The three root-cutting methods all have remarkable production-increase effect. Spike number decreased, grain number per spike and 1000-grain weight increased evidently, the average grain yield increased by 9.96~11.41%. As a matter of fact, the combine of shovels & blades has the best root-cutting effect, and also has the most remarkable production increase. It showed that the more roots being cut, the higher production increased.更多还原