微小零件装配和影响可靠操作的粘附力研究

发布时间：2018-07-05 17:31

本文选题：精密装配 + 可靠操作　；参考：《大连理工大学》2016年硕士论文

【摘要】：零件装配是微小惯性器件生产制造过程中的重要环节,直接影响器件的性能。装配的可靠性是实现微小零件装配系统设备应用的保证。随着零件的微小化,表面力对零件拾取与释放的影响增加,尤其是在释放过程中,吸附头与零件之间的表面力导致的位置误差会影响装配精度,因此微小惯性器件装配中零件的可靠拾取与释放是装配成功与否的关键。本文需要装配的微小惯性器件由七个零件组成,其中三个为薄片类零件,最小质量为0.4g,零件的拾取方式采用真空吸附。为了减小装配时粘附力对零件装配精度带来的影响,分别对范德华力、静电力和毛细作用力三种粘附力进行了分析,研究了不同力的产生机理与影响因素,为减弱粘附力提供了一定的理论参考。设计并搭建了微力测量装置用于测量装配作业时吸附头和零件接触表面间的粘附力,针对上述三个零件,分别研究了不同的分离速度、加载的装配力和时间、吸附头材料及环境湿度等参数对粘附力的影响规律。测量实验结果表明：分离速度、加载装配力时间对橡胶吸附头和硅、镀金材料零件间的粘附力影响较大,粘附力随着参数值的增加显著增大,而对吸附头和氮化铝材料零件间的粘附力影响微弱；在加载的20-80mN装配力范围内变化时,橡胶吸附头和三种材料零件间的粘附力基本保持稳定；聚四氟乙烯(PTFE)材料吸附头能显著减小和三种材料零件间的粘附力；环境湿度对橡胶吸附头和三种材料零件间的粘附力影响显著,粘附力都随着湿度的增加而显著增大,但当湿度超过60%时,硅材料零件和橡胶吸附头间的粘附力大小基本稳定。综上,以吸附方式拾取微小零件时作业环境的湿度应尽量小,吸附头采用PTFE材料,分离速度和装配力加载时间应在合适的范围内选择较小的值有利于减小粘附力以提高装配的精度。上述研究工作为微小薄片类零件的可靠释放与高精度装配提供了技术手段和实验依据。针对已有装配系统流程单一,不灵活的缺点,本文对其进行优化,研究制定了可从不同的零件开始装配的装配流程,在Microsoft Visual C++平台上开发了精密装配系统的控制软件程序,系统可选择从任意零件开始完成后续整个组件的装配任务。装配实验结果表明,优化后的装配软件提高了系统装配效率和灵活性。
[Abstract]:The assembly of parts is an important part in the manufacturing process of micro inertial devices, which directly affects the performance of the devices. The reliability of assembly is the guarantee to realize the equipment application of small parts assembly system. With the miniaturization of the parts, the influence of the surface force on the pickup and release of the parts increases, especially in the process of release, the position error caused by the surface force between the adsorbent head and the parts will affect the assembly accuracy. Therefore, the key to successful assembly is the reliable pickup and release of parts in the assembly of micro inertial devices. The micro inertial device which needs to be assembled in this paper consists of seven parts, three of which are thin sheet parts with a minimum mass of 0.4 g. Vacuum adsorption is used to pick up the parts. In order to reduce the influence of adhesion force on assembly precision of parts, three kinds of adhesion forces, namely van der Waals force, electrostatic force and capillary force, were analyzed, and the mechanism and influencing factors of different forces were studied. It provides a theoretical reference for reducing the adhesion force. A micro force measuring device is designed and built to measure the adhesion force between the adsorbent head and the contact surface of the parts during assembly operation. For the three parts mentioned above, the different separation speed, the loading assembly force and the time are studied respectively. The influence of adsorption head material and environmental humidity on adhesion force. The experimental results show that the separation speed, loading and assembling time have great influence on the adhesion between the rubber adsorbent head and silicon, and the adhesion force increases with the increase of the parameter value. The adhesion force between the adsorbent head and the aluminum nitride parts is weak, and the adhesive force between the rubber adsorbent head and the three material parts remains stable when the loading range of 20-80mN assembly force is changed. Polytetrafluoroethylene (PTFE) material adsorption head can significantly reduce the adhesion force between the three material parts, and the environmental humidity has a significant effect on the adhesive force between the rubber adsorption head and the three materials parts, and the adhesion force increases with the increase of humidity. However, when the humidity exceeds 60, the adhesion between the silicon parts and the rubber adsorption head is basically stable. In summary, the working environment humidity should be as small as possible when picking up small parts by adsorption. PTFE material is used for adsorption head. The separation speed and the loading time of assembly force should be chosen in a suitable range to reduce the adhesion force and improve the assembly accuracy. The above research work provides the technical means and experimental basis for reliable release and high precision assembly of micro sheet parts. Aiming at the disadvantage of single and inflexible assembly system flow, this paper optimizes the assembly process, studies and formulates the assembly process that can be assembled from different parts, and develops the control software program of precision assembly system on Microsoft Visual C platform. The system can choose from any part to complete the assembly task of the following whole component. The assembly experiment results show that the optimized assembly software improves the assembly efficiency and flexibility of the system.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG95

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