【作者】 刘志青；

【导师】 聂松辉；

【作者基本信息】 湘潭大学 ， 机械工程， 2020， 硕士

【摘要】 随着“中国制造2025”的提出以及美国制造业的重振,标志着制造业对于一个国家综合国力的影响十分重要,同时对于中国的制造业有了更加明确的追求目标,不仅仅是面对航天航空高端制造领域,同时也涵盖了轻工业领域。凸轮连杆机构作为一种常用的组合机构,广泛应用在农业、包装、印刷、纺织等多个领域,用来实现复杂的连续运动。目前对于这一类的组合机构或多或少存在着单一化处理的不足,论文以盘形凸轮加四杆机构组合而成的药品出盒机构作为研究对象,从设计、优化以及多因素下的可靠度等展开研究,主要完成了如下研究工作:提出了凸轮-连杆组合机构的出盒机构设计方案,推导了凸轮轮廓曲线方程,分析了该轮廓曲线下摆杆的运动学性能。采用三位置刚体导引法对摇杆机构进行了尺度综合,并建立了机构运动学与动力学模型,分析了吸盘末端在理想状态下的速度、加速度以及各运动副处的径向力。构建了出盒机构pro/E骨架模型,仿真分析获得了最大凸轮压力角与最小曲率半径,并对机构参数进行了敏感度分析,确定了优化参数,建立了以加速度为目标的优化模型,在满足最大角位移为90°条件下,使优化后最大加速度下降了23.27%。分别考虑原始尺寸误差、间隙,以及磨损的影响,建立了出盒机构的运动精度模型,得到了各因素下机构的运动误差曲线。分析结果表明,原始误差下带来的影响比间隙和磨损带来的影响大,但随着工作时间的增长,磨损导致机构的误差变大。同时,综合考虑三种因素,构建了出盒机构可靠度模型,并对不同许用误差下的关键位置可靠度进行了分析。建立了出盒机构三维模型,并对考虑运动副间隙时的出盒机构,分别进行了刚体运动学与动力学分析以及刚柔耦合运动学与动力学分析。分析结果表明间隙的增加会导致机构的运动速度与加速度值突变,从而引发机构运行时振动加剧,同时,相对于刚体分析时,部件柔性下机构的速度与加速度数值稍有收敛,各运动副处最大径向力有大幅度下降,曲线尖点减少明显,表明部件柔性处理一定程度会减少机构碰撞力度和磨损。更多还原

【Abstract】 With the proposal of "Made in China 2025" and the revitalization of the US manufacturing industry,it indicates that the manufacturing industry has a very important influence on the comprehensive national strength of a country.At the same time for China’s manufacturing industry with the pursuit of more specific goals,which is not only facing the high-end aerospace manufacturing field,but also covering the light industry field.As a common combination mechanism,cam linkage mechanism is widely used in agriculture,packaging,printing,textile and other fields to achieve complex continuous motion.At present,there is more or less a lack of single treatment for this kind of combination mechanism.This paper takes the drug delivery mechanism composed of disc cam and four-bar mechanism as the research object,and conducts research from the aspects of design,optimization and reliability under multiple factors.Mainly completed the following research work:This paper presents a design scheme of the cam-link combination mechanism,deduces the equation of the cam contour curve,and analyzes t the kinematics performance of this profile curve.The three-position rigid body guidance method is used to synthesize the scale of the rocker mechanism,and the kinematics and dynamics model of the mechanism is established.Constructed out of the box body skeleton pro/E model,simulation analysis to obtain the maximum pressure Angle of cam and the minimum radius of curvature,and the sensitivity analysis was carried out on the structure parameters,the optimized parameters,aimed at the acceleration optimization model is established,under the condition of meet the maximum angular displacement is 90 °,the maximum acceleration decreased by 23.27% after optimization.Considering the influence of the original size error,clearance and wear,the motion precision model of the boxed mechanism is established,and the motion error curve of the mechanism under each factor is obtained.The analysis results show that the influence of the original error is greater than that of the gap and wear,but with the increase of working time,the wear leads to the increase of the error of the mechanism.At the same time,the reliability model of the out-box mechanism is constructed by taking three factors into consideration,and the reliability of the key position under different allowable errors is analyzed.The 3d model of the boxed mechanism was established,and the kinematics and dynamics analysis of the boxed mechanism and the coupling kinematics and dynamics analysis of the rigid body were carried out respectively.Analysis results show that the increase of the gap leads to movement speed and the acceleration value mutation,triggering mechanism runtime vibration,at the same time,relative to the rigid body analysis,component institutions under flexible rod numerical have convergence,velocity and acceleration of each movement place pair place maximum radial force has dropped dramatically,curve point reduce obviously.It shows that the flexible treatment of components will reduce the collision force and wear of the mechanism to a certain extent.更多还原