新型耕耘机的前置深松部件研究

发布时间：2018-05-01 05:15

本文选题：深松部件 + 前置悬挂　；参考：《西南大学》2017年硕士论文

【摘要】：土壤深松技术作为耕作技术中的重要组成部分,能够打破因长期使用传统耕作方式而产生的犁底层,有效改善土壤结构,促进作物生长。目前,深松机具大多是与大中型拖拉机匹配采用后置悬挂进行作业。我国丘陵山区面积占国土面积的2/3以上,但由于其地形不平坦等因素导致大中型拖拉机并不适用,因此,在丘陵山区进行深松作业十分困难。针对这一问题,本文对深松部件前置进行了分析研究,使其能够与新型耕耘机匹配,在丘陵山区进行深松作业,本文主要包括以下研究内容:(1)前置深松部件的研究选择间隔深松作业方式,并分析深松机具的作业要求,确定耕幅为1.2m,深松深度为40cm,配置两把深松铲,铲间间距为60cm。通过对三种常见深松机型的比较,选择以自激振动型深松机为本文深松机型。分析深松铲后置悬挂时其提升和入土的运动轨迹,设计具有相同运动轨迹的平行四杆前悬挂机构,确定前悬挂机构各杆件的尺寸。根据自激振动原理,设计自激振动机构。结合机架安装尺寸和深松作业要求,设计相对应的深松铲。最后通过UG建立前悬挂机架、自激振动机构和深松铲的三维模型并进行装配,完成前置深松部件的初步设计。(2)深松部件前置悬挂作业的理论分析对深松铲和机架在作业时的受力进行理论分析。根据悬挂的设计要求和校核准则,对深松铲的入土性能、耕深稳定性和纵向稳定性进行分析,结果表明,本文所设计的前置悬挂作业部件均满足上述要求。通过试验和计算得出深松部件前置悬挂使得耕耘机的重心前移了118.23mm,通过前后分组悬挂可使耕耘机获得更大的压力中心位移允许值。通过对深松旋耕联合作业时整机的受力分析得知,深松部件前置悬挂作业可以增大拖拉机的附着力,从而提高其切线驱动力,进一步提高牵引力、牵引功率和牵引效率。通过理论分析验证了前置深松部件设计的合理性,并为后续的数值模拟研究和静态分析奠定基础。(3)深松作业过程的数值模拟研究取西南大学农场旱田土壤为样本,测得土壤的基本参数。基于光滑粒子流体动力学(SPH)构建出深松铲深松土壤的理想模型。利用ANSYS/LS-DYNA和LS-PREPOST对该模型进行数值模拟研究,得到深松作业时土壤施加在深松铲上的最大阻力为2560N,平均功耗为13kW,表层土壤扰动较小。通过数值模拟研究,能够初步估算作业效果和深松所需功耗,并为前置悬挂机架的静态分析奠定基础。(4)前置悬挂机架的静态分析利用数值模拟分析中得到的深松阻力求出前置悬挂机架的受力。利用Workbench对前置悬挂机架进行静力学分析和模态分析,得到前置悬挂机架在作业时的最大位移为3.3904mm,最大应力为96.63MPa,均满足设计要求。前六阶的固有频率分布在30~170Hz之间。通过静态分析可知机架的薄弱部位为机架与机头的螺栓连接处,将该处改用为U型螺栓连接,并通过添加筋肋提高平行四杆机构的强度,完善前置深松部件的设计。
[Abstract]:Soil deep loosening technology, as an important part of tillage technology, can break the plow bottom which is produced by traditional traditional farming methods, effectively improve the soil structure and promote the growth of crops. At present, the deep loosening machinery is mostly matched with the large and medium tractors by the rear suspension to carry out the operation. It is more than 2/3, but the large and medium-sized tractors are not suitable for its uneven terrain and so on. Therefore, it is very difficult to carry out deep loosening operation in Hilly and mountainous areas. In this paper, this paper analyses the preposition of the deep loosening parts, so that it can match the new cultivator and carry out deep loosening operation in Hilly and mountainous areas. This paper mainly includes The following research contents are as follows: (1) the study of the preformed deep loosening parts selects the interval deep loosening operation mode, and analyzes the operation requirements of the deep loosening machine. It is determined that the ploughing width is 1.2m, the depth of the deep loosening is 40cm, the two deep loosening shovels are arranged and the space between the shovels is 60cm. through comparison of the three kinds of common deep loosening machines, the self excited vibration type deep looser is selected as the deep loosening machine. A parallel four bar front suspension mechanism with the same trajectory is designed to determine the size of each bar in the front suspension mechanism. The self excited vibration mechanism is designed according to the principle of self excited vibration. The corresponding deep loosening shovel is designed in the light of the principle of self excited vibration. Finally, the corresponding deep loosening shovel is designed with the installation size of the frame and the requirement of deep loosening. Finally, the U is designed. G set up the front suspension frame, the three dimensional model of the self excited vibration mechanism and the deep loosening shovel, and carry out the assembly to complete the preliminary design of the preformed deep loose parts. (2) theoretical analysis of the pre suspension operation of the deep loosening parts and the theoretical analysis of the force of the deep loosening shovel and the frame in the operation. The performance, ploughing stability and longitudinal stability are analyzed. The results show that the pre suspension working parts designed in this paper meet the above requirements. Through the test and calculation, the pre suspension of the deep loose parts makes the center of gravity of the cultivator move forward 118.23mm, and the cultivator can get a greater pressure center displacement through the front and back group suspension. According to the force analysis of the whole machine during the combined operation of deep loosening rotary tillage, it is found that the pre suspension operation of the deep loose parts can increase the adhesion of the tractor, thus improve the driving force of the cutting line, further improve the traction power, traction power and traction efficiency. The numerical simulation study and static analysis lay the foundation. (3) the numerical simulation of the process of deep pine operation is taken as the sample of the soil in the dry field of the Southwestern University, and the basic parameters of the soil are measured. Based on the smooth particle hydrodynamics (SPH), an ideal model for deep loosened soil is constructed. The model is numerically simulated with ANSYS/LS-DYNA and LS-PREPOST. The simulation study shows that the maximum resistance of soil on the deep loosening shovel is 2560N, the average power consumption is 13kW, and the surface soil disturbance is small. Through numerical simulation, it can preliminarily estimate the operation effect and the power consumption of the deep loosening, and lay the foundation for the static analysis of the front suspension frame. (4) the static analysis of the front suspension frame The force of the front suspension frame is calculated by the deep loosening resistance obtained in the numerical simulation analysis. The static analysis and modal analysis of the front suspension frame are carried out by Workbench. The maximum displacement of the front suspension frame is 3.3904mm and the maximum stress is 96.63MPa, which all meet the design requirements. The natural frequency distribution of the first six orders is in 30~17 0Hz. Through static analysis, it can be found that the weak part of the frame is the bolt connection of the frame and the head of the machine. It will be used as the U type bolt connection, and the strength of the parallel four bar mechanism is improved by adding rib rib, and the design of the preformed deep loosened part is perfected.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S222

【参考文献】