柔顺机构的软化和静态平衡设计

发布时间：2019-02-24 12:01

【摘要】：柔性机构是一种利用机构（或构件）本身的挠性获得部分或全部运动的机构，其减少了机构的零件数目，避免了机构的一些装配环节，使机构更加简单、可靠，且构件之间无缝隙和摩擦，提高了机构的运动精度及使用寿命。然而，利用柔性机构中柔性构件的弹性变形来实现运动时，柔性机构需要额外的输入使弹性构件发生变形，导致机构中非期望的能量存储，其存储的能量在弹性构件恢复形变时以回程反力做功的形式释放，这种柔性机构的储能释能特性在一定程度上降低了其使用性能，如使驱动力的增加、工作力反馈的无效感知等。首先，本文对柔性机构做了简要的介绍，说明了柔性机构的基本设计方法和应用领域；后提出了柔性机构软化的概念、实现柔性机构软化与静态平衡的优化设计方法及其步骤。其次，应用所述的方法，设计了一些实现了软化或静态平衡的柔性机构：基于柔性四杆机构优化设计了可用于汽车后盖开闭的柔性机构，其不需要额外的驱动装置便可呈现双稳态特性，，同样的对用柔性四杆机构实现绕定轴转动重物的静态平衡机构也做了优化设计；优化设计了多稳态机构的参数，使得两多稳态机构并联叠加后在区段上实现静态平衡，并用ANSYS对其做了有限元静力分析与检验；在分析空间6R Sarrus机构运动学的基础上，分析了全柔性或部分柔性Sarrus机构的多稳态特性，后通过叠加形成的多稳态特性实现了柔性Sarrus机构的静态平衡特性。最后，对本文中所提出的柔性机构软化及静态平衡的方法及应用该方法所设计机构的效果做了相应的分析与总结，并对未来的工作做出了展望。本文所提出的使柔性机构软化及静态平衡的方法成功实现了柔性机构在特定运动段内机构刚度的减小或为零，使得柔性机构的应用范围更加广泛，并使其可在精确度要求高的MEMS中广泛的应用，提高了使用性能，易于维护，且用很小的驱动机构即可驱动，减小了机构的体积与重量，使之更加安全可靠。
[Abstract]:Flexible mechanism is a kind of mechanism which can obtain part or all motion by using the flexibility of the mechanism (or component) itself. It reduces the number of parts of the mechanism, avoids some assembly links of the mechanism, and makes the mechanism simpler and more reliable. And there is no gap and friction between the components, which improves the kinematic accuracy and service life of the mechanism. However, when the elastic deformation of the flexible member in the flexible mechanism is used to realize the motion, the flexible mechanism needs additional input to make the elastic member deform, resulting in the unexpected energy storage of the mechanism. The stored energy is released in the form of backhaul counterforce work when the elastic member recovers the deformation. The energy storage and release characteristics of the flexible mechanism reduce its performance to a certain extent, such as increasing the driving force. Invalid perception of feedback of work force, etc. Firstly, this paper briefly introduces the flexible mechanism, explains the basic design method and application field of the flexible mechanism, and then puts forward the concept of the flexible mechanism softening, and the optimal design method and its steps to realize the softening and static balance of the flexible mechanism. Secondly, some flexible mechanisms with softening or static balance are designed by using the method. Based on the flexible four-bar mechanism, the flexible mechanism that can be used to open and close the rear cover of automobile is optimized. It can present bistable characteristics without additional driving device. The same static balancing mechanism which uses flexible four-bar mechanism to realize the rotation of weight around the fixed axis is also optimized. The parameters of the multi-stable mechanism are optimized and the static balance of the two mechanisms is realized by parallel superposition. The finite element static analysis and test are carried out with ANSYS. On the basis of kinematics analysis of spatial 6R Sarrus mechanism, the multi-steady state characteristics of fully flexible or partially flexible Sarrus mechanism are analyzed, and the static equilibrium characteristics of flexible Sarrus mechanism are realized by superposition of multi-steady state characteristics. Finally, the methods of softening and static balance of flexible mechanism proposed in this paper and the effect of the mechanism designed by this method are analyzed and summarized, and the future work is prospected. The method of softening and static balance of the flexible mechanism proposed in this paper has successfully realized the reduction or zero of the stiffness of the flexible mechanism in the specific motion segment, which makes the application of the flexible mechanism more extensive. It can be widely used in MEMS with high precision, and it improves the performance, easy to maintain, and can be driven by very small driving mechanism, which reduces the volume and weight of the mechanism and makes it more safe and reliable.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH112

【引证文献】