【作者】 李明江；

【导师】 宋永伦； 张军；

【作者基本信息】 北京工业大学 ， 机械电子工程， 2006， 硕士

【摘要】 铝合金点焊作为一种行之有效的焊接方法在航空、航天产品的生产中得到了广泛的应用,但是到目前为止真正能应用到生产线上的点焊质量在线监测系统非常少,目前铝合金点焊的质量检测主要还是依赖人工或X射线检测。虽然很多学者针对铝合金点焊的监测方法进行了卓有成效的研究,但是大部分的成果仍然处于实验室研究阶段。本课题正是在这一背景下提出的。本课题为航天科技集团某机械厂项目,该厂目前存在的主要问题是飞溅及熔核尺寸不合格,因此本课题的研究也主要针对这两方面缺陷进行。本文工作中构建了以电极压力、电极位移、焊接电流及电压作为铝合金点焊质量评定特征信息的铝合金点焊质量在线监测系统。同时构建了基于铝合金点焊质量在线监测系统的数据库,通过LabVIEW SQL Toolkit完成数据库与LabVIEW监测系统的连接,实现了焊点相关信息的适时记录和查询功能。本课题将在工业过程控制中应用广泛的统计过程控制技术(SPC)应用到铝合金点焊生产,通过其对数据库信息的统计分析实现对铝合金点焊质量在线监测系统参数的优化。通过大量的验证实验及针对实际产品的生产监测,对本监测系统进行了不断的优化。目前本系统已经达到了较高的焊点质量判定精度,并已应用于多个型号航天产品的铝合金点焊生产中。随着数据库信息的增多,统计过程控制技术的优势也将进一步发挥,使监测系统的焊点质量评定更加准确。更多还原

【Abstract】 Aluminum alloy spot welding has been widely used in aerial production. But an effective way hasn’t been found for on-line inspection of the nugget’s quality。Until now, and most of the inspecting works are done by X-ray, ultra-sonic or mechanical ways. Though many researchers have made lots of efforts to solve this problem, but most of their works are still under test in laboratory. That’s the background of why we do this work to meet the urgent need of the industry.This work is for one factory of CASC, the major faults in aluminum spot welding are expulsion and unqualified size of nugget, so the aim of our work is to monitor the welding process and find these possible faults. The aluminum spot welding on-line monitoring system was constructed. Welding current and voltage, tip displacement and tip pressure are selected as the characteristic signals to measure and estimate the quality of the nuggets. In order to memorize and query the spot welding process information, a database was constructed and connected with the on-line monitoring system through LabVIEW SQL Toolkit. The Statistical Process Control (SPC) is used to estimate and optimize the critical value and process parameters.After doing a lot of experiments with testing pieces and also factual products, the system has been used in different types of aerial products’spot welding and achieved on-line inspection with high precision. It has been constantly optimized with the database becoming more abundance, and the predominance and the estimating precision of the nuggets’quality will be more accuracy.更多还原