大豆耕播机触土关键部件设计及测试技术研究

发布时间：2018-06-05 01:14

本文选题：大豆耕播机 + 耕作部件　；参考：《吉林大学》2017年硕士论文

【摘要】：耕播联合作业机组一次下地能完成耕整地和播种等多项作业,能高效地完成农作物的种植,因此,大豆耕播机是实现大豆种植机械化最重要的机具之一。大豆耕播机机组完成耕地、整地和播种等作业机械的任务,需要连续地与田间土壤接触进行作业,这对大豆耕播机触土部件的工作性能具有很高的要求。本文对大豆耕播机触土部件中的耕作和镇压关键部件做了相关研究,主要研究了大豆耕播机耕作部件减阻耐磨耦合仿生表面结构的制备方法及其作业阻力参数的测试,以及大豆耕播机镇压装置镇压力参数的测试。针对耕作部件既要提高耐磨性又要保证强度存在矛盾、以及耕作阻力大的问题,本文提出了一种通过构建仿生表面结构和控制工艺(设置冷铁)来设计结构/材料二元耦合仿生表面结构的方法。运用此方法采用球墨铸铁材料进行砂型铸造制备试样,并进行了相关试验。微观组织分析表明:单纯通过构建仿生表面结构或局部设置小型冷铁的方法,试样表面结构局部均未能形成白口铁组织,而上述两种方法的结合运用,可耦合实现球墨铸铁试样仿生表面结构的白口化。显微硬度和划痕试验表明:耦合仿生表面结构具有较高的局部硬度,相比于芯部基体,其显微硬度值平均提高了35.71%,而形成相同宽度的划痕时,其所需载荷是芯部基体的1.16倍。磨料磨损试验结果表明:构建仿生表面结构和设置冷铁试样的磨损量均小于无结构无冷铁试样,构建仿生表面结构且设置冷铁试样的磨损量最小。各试验结果说明耦合仿生表面结构具备了内部球墨铸铁韧性好、外部表面白口组织硬度高的特点,从而兼顾部件的耐磨性和机械性能。水润湿性试验结果表明:耦合仿生表面结构处水接触角高于芯部组织的水接触角,其接触角增大了14.91%,更大的接触角有利于降低土壤粘附,表面水接触角的梯度分布有利于实现粘附土壤脱附。磨料磨损试验中受力分析表明:仿生表面结构对样品的切向力有较大的影响,构建仿生表面结构的试样切向受力最小。各试验结果说明耦合仿生表面结构具有一定的减阻效果。运用结构和材料二元耦合仿生设计的方法,加工制备了具有仿生表面结构的耦合仿生双翼型深松铲尖。针对耕作部件(如深松铲、起垄铲等)田间作业时阻力采集困难和相关阻力测试装置结构复杂、维护使用成本高、缺乏过载保护等问题,设计了一种耕作部件作业阻力测试装置(TRTD),并以双翼型深松铲为例,建立了包含修正系数k与扭簧转角θ、耕深H、耕速V、土壤容积密度ρ、深松铲结构参数等换算关系的耕作阻力测试方法,与传统三点式作业阻力测试系统(TTD)在6组耕作条件下进行了土槽对比试验。精度分析结果表明TRTD相比于TTD的最大相对误差为1.34%,波动性分析结果表明TRTD与TTD的波动幅值比较接近,两者最大相对偏差不超过5%。采用本文设计的阻力测试装置对比分析了本文设计的仿生双翼型深松铲尖和传统双翼型深松铲尖的水平耕作阻力,试验结果表明,仿生双翼型深松铲尖一定程度上减小了深松铲的耕作阻力。本文提出了一种基于仿形弹性镇压辊的镇压力测试方法,采用等效土壤坚实度的方法,建立了适应于播种表土层(0-100 mm)的镇压辊偏心量-等效土壤坚实度-镇压力的数学关系模型。土槽验证试验结果表明,采用镇压辊镇压力测试方法测量得的土壤坚实度与人工实地测量的土壤坚实度比较贴合,且在3种不同的含水量条件下都比较适用。基于理论分析和土槽试验,进行了田间综合试验:1)利用耕作阻力测试装置对深松铲尖进行耕作阻力田间试验,对两种类型的深松铲尖进行了阻力对比分析。2)进行镇压力田间试验,考察基于弹性镇压辊的镇压力测试方法的田间工作效果。
[Abstract]:The ploughing and sowing unit can complete the ploughing and sowing and so on at one time, and can efficiently complete the planting of the crops. Therefore, the soybean ploughing and seeding machine is one of the most important machines to realize the mechanization of soybean planting. In this paper, the key parts of the tillage and repression in the soil parts of the soybean ploughing and sowing machine are studied in this paper. The preparation methods and the resistance parameters of the coupling bionic surface structure of the resistance and wear resistance of the tillage parts of the soybean ploughing sowing machine are mainly studied in this paper. The test, as well as the test of the pressure parameters of the town pressing device of the soybean ploughing machine. In view of the problems of improving the wearability and the strength of the tillage, and the large resistance to the tillage, a bionic structure / material two element coupling surface structure is designed by the construction of a bionic surface structure and a control process (setting cold iron). Using this method, the spheroidal graphite cast iron material was used to make sand mold preparation samples and the related tests were carried out. The microstructure analysis showed that the surface structure of the sample was not formed by the method of constructing the bionic surface structure or the local setting of the small cold iron, and the combination of the above two methods could be used. The microhardness and scratch test show that the coupling bionic surface structure has high local hardness, and the microhardness value of the coupled bionic surface structure is higher than that of the core substrate by 35.71%, while the load required for the same width is 1.16 times that of the core matrix. The results show that the wear amount of the bionic surface structure and the set of cold iron specimen is less than that of the non structure non cold iron specimen. The structure of the bionic surface structure and the wear quantity of the cold iron specimen are the smallest. The results show that the coupling bionic surface structure has the characteristics of good toughness of the inner ductile iron and the high hardness of the white surface on the external surface. The water wettability test results show that the water contact angle of the coupled biomimetic surface structure is higher than the water contact angle of the core, and the contact angle increases by 14.91%. The larger contact angle is beneficial to the reduction of soil adhesion, and the gradient distribution of the surface water contact angle is beneficial to the desorption of soil adhesion. The stress analysis in the loss test shows that the bionic surface structure has a great influence on the tangential force of the sample, and the specimen with the bionic surface structure has the smallest shear stress. The results show that the coupling bionic surface structure has a certain drag reduction effect. The bionic table is prepared by the method of two element coupling bionic design of the structure and material. In the field of farming parts (such as deep loosening shovel, ridging shovel, etc.), the resistance acquisition difficulty and the related resistance testing device are complex, the maintenance cost is high, and the overload protection is short of overload protection. A kind of TRTD is designed, and the double wing type deep loosening shovel is designed. For example, the method of resistance testing is established, which includes the correction coefficient K and the torsion spring angle theta, the ploughing depth H, the tillage speed V, the soil volume density p, the deep loosing shovel structure parameters and so on, and the traditional three point resistance test system (TTD) has carried out the soil grooves comparison test under the 6 groups of tillage conditions. The accuracy analysis results show that the TRTD is the largest compared to the TTD. The relative error is 1.34%. The fluctuation analysis shows that the fluctuation amplitude of TRTD and TTD is close, and the maximum relative deviation is not more than 5%.. The resistance testing device designed in this paper is used to compare and analyze the horizontal tillage resistance of the bionic double wing spade tip and the traditional double wing type deep loosening shovel. A deep loosening shovel tip reduces the tillage resistance of the deep loosening shovel to a certain extent. In this paper, a new method of pressure testing based on an imitation elastic repression roll is proposed. By using the method of equivalent soil firmness, a mathematical relationship model of the eccentricity of the repression roll, which is suitable for the sowing surface layer (0-100 mm), is established. The test results show that the soil firmness measured by the repression roll town pressure test method is close to the soil firmness measured by artificial field, and is more suitable under 3 different water content conditions. Based on the theoretical analysis and soil trough test, the field fully mechanized test is carried out: 1) the use of tillage resistance testing device for deep loosening is made. The field experiment on the resistance of the shovel was carried out, and the resistance contrast analysis of two types of deep slack shovel pointed.2) was carried out in the field test of pressure in the town. The effect of the field work on the pressure test method based on the elastic pressing roll was investigated.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.24

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