航天用行程开关耐力学环境设计方法研究

发布时间：2018-01-02 11:32

本文关键词：航天用行程开关耐力学环境设计方法研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：行程开关又称限位开关,是一种常用的小电流主令电器。其工作原理为:当外力施加于行程开关的按钮时,开关内部的结构件通过机械传动使触头动作进而实现接通或分断控制电路,达到一定的控制目的。由于开关内部的触点与触头为弹性接触,因此,在振动、冲击、恒加速度等力学环境综合作用下存在着接触可靠性的问题。接触系统是行程开关实现电路切换功能的核心执行部件。接触系统的固有频率与响应振幅特性直接影响闭合触点在振动和冲击环境下的接触可靠性;而接触压力直接影响闭合触点在恒加速度环境下的接触可靠性。研究行程开关耐力学环境性能,可具体到研究接触系统的固有频率、响应振幅特性和接触压力等问题上,由于在动态条件下,这些参数的变化均呈现为非线性规律,因此研究工作较少。文章介绍了一种常见的行程开关的桥接式接触系统。通过设定边界条件将簧片物理模型简化替换为悬臂梁模型。而后,将悬臂梁模型与单自由度弹簧振子模型进行类比,得到在一定条件下二者振动特性相似的结论。进而将这种相似结论推广到整个接触系统,经进一步等效替换,将接触系统物理模型替换为并联弹簧振子。在固有频率保持不变的基础上进行等效替换,将接触系统的非线性问题转化为线性问题,并在此基础上开展模态分析:结合单自由度振动体系固有频率通用表达式和并联等效原理推算出接触系统的固有频率表达式,并分别计算了簧片和接触系统的固有频率,通过有限元仿真软件建立有限元模型进行模态仿真,通过理论和仿真分析结果的对比验证了分析思路的正确性。在模态分析的基础上开展振动、冲击、恒加速度等力学环境作用下接触系统桥接结构的动态特性。利用经典力学、材料力学、振动学相关理论,分别建立了不同力学环境下接触系统的运动方程,分别进行振动谐响应,冲击响应和加速度应变分析;同时,利用有限元分析软件再次验证了数学模型和理论分析结论的正确性;并结合两方面分析结论提出了在复杂力学环境下确保行程开关接触系统接触可靠性的合理判据。作为一种设计思路,文章的结论对于位置开关类器件内部接触系统的参数设计具有一定的参考价值,为提高有机械触点的开关电器在振动、冲击、恒加速度等力学环境下的接触可靠性提供了一些的分析思路和方法。
[Abstract]:Also called the travel switch limit switch, is a small current commonly used master appliances. Its working principle is: when the external force applied to the switch button, a switch internal structure by mechanical transmission to make the contact action and get through or cut off the control circuit to control the purpose. Because of contact, contact the internal elastic contact switch and so on vibration, shock, constant acceleration and other mechanical environment under existing contact reliability problems. The contact system is the core to achieve the circuit switching function of the travel switch component. Contact the inherent frequency and amplitude response characteristics directly affect the contact reliability of closed contact in vibration and shock environment next; and the contact pressure directly affects the contact reliability of closed contact in constant acceleration environment. Research on stroke switch endurance environment performance, can be specific to the study of contact The natural frequency of the system response, amplitude characteristics and contact pressure on the dynamic condition, the changes of these parameters are presented as nonlinear rules and therefore less research. This paper introduces the bridge type contact system of a common switch. By setting the boundary conditions will be simplified as the cantilever beam model to replace reed model. Then, the cantilever beam model with single degree of freedom oscillator model by analogy, under certain conditions, the two vibration characteristics of a similar conclusion. Then the similar conclusion to the whole contact system, by further equivalent replacement, the contact system physical model replacement for parallel spring vibrator. The base remained unchanged on the equivalent substitution in the natural frequency, the system will contact nonlinear problem into a linear problem, and on this basis to carry out modal analysis with the vibration of single degree of freedom Calculate the natural frequency of contact system natural frequency expressions of general expressions and parallel equivalent principle, natural frequency and reed contact system are calculated, through the finite element simulation software to establish the finite element model of modal simulation, the comparison between theoretical analysis and simulation results verify the correctness of the analysis method. The vibration, impact on based on modal analysis, the dynamic characteristics of the bridge structure of the contact system of constant acceleration and other mechanical environment. By using classical mechanics, material mechanics, vibration theory, the equations of motion are established with mechanical environment contact system, respectively, harmonic response analysis, impulse response and acceleration at the same time, using the finite strain; element analysis software again to verify the correctness of the mathematical model and the theoretical analysis conclusion; and combined with the analysis of two aspects of conclusion put forward in the complex Ensure a reasonable criterion of travel switch contact system, the contact reliability of mechanical environment. As a kind of design idea, the conclusion has a certain reference value for the parameter design of position switch devices within the contact system, in order to improve the electrical mechanical contact switch in the vibration, impact, the contact reliability constant acceleration mechanical environment provides some analysis ideas and methods.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V442

【引证文献】