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为了减少整车生产车间焊接自动化生产线机器人点焊中的电极帽粘脱故障,提高白车身焊接效率,采用故障树分析方法对粘脱故障进行分析。以某汽车生产企业的焊接主线为例,参照主线10台点焊机器人的103工作小时故障案例,结合基于故障树模型分析的方法,建立电极帽粘脱故障树模型,并进行了定性分析和定量分析。分析了故障树的最小割集,判断出影响该故障的主要底事件,采用不交布尔代数法求出底事件发生概率和概率重要度,提出了对该种现场故障的排除方法,为该焊接过程的方法改进和故障维修提供了理论依据,也为焊接主线的生产管理提供参考。 相似文献
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随着人工成本的不断提高及工业化机器人的相关产品不断成熟,在汽车工业中普遍开始大规模应用工业机器人及自动化生产线。目前,在汽车白车身生产中的主要连接技术——电阻点焊,特别是使用工业机器人自动化生产线中,电极自动修磨工艺得到广泛应用,其在极大提高生产效率的同时,降低了大量的人工成本。电极修磨的质量好坏,能够直接影响焊点的质量及焊点质量的稳定性,从而影响到车身的整体强度。电极修磨质量的优化及调整也成为了汽车车身点焊的重要工作内容。 相似文献
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介绍了电阻点焊电极位移和焊接电流的检测基本原理,并分析了基于此原理所研制的微机检测系统的设计思想及硬,软件。 相似文献
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本文研究了电极的不同长度,水冷孔直径对工作面焊接硬度和损耗量的影响。研究表明,电极只有保持一定的工作长度和水冷孔直径,才有较高的焊接硬度和使用寿命。 相似文献
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介绍了自70年代以来几种有代表性的点焊控制方法的原理及具体组成;比较了其优缺点,介绍了国际上关于点 控制器的研究动向。 相似文献
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镀锌钢板白车身的点焊喷溅问题 总被引:1,自引:0,他引:1
通过对点焊喷溅形成机理的分析,结合镀锌钢板电阻点焊的特殊性,对白车身制造过程中产生点焊喷溅的影响因素进行了详细的分析。并结合生产现场的实际情况,对降低点焊喷溅的发生提出了相应的解决措施。对于提高车身表面质量、减低工人的劳动强度具有一定的实践意义。 相似文献
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高速走丝线切割机在运行一段时间后,贮丝筒两端电极丝会出现一端紧一端松的现象,使工件加工表面出现明显的倒向痕.运行的时间越长,此现象越明显,加工的精度越差.在接触到的机床范围内,据初步统计故障率约达1/3.如用张力仪严格检查,几乎所有的机床都存在这个问题. 相似文献
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为促进伺服焊枪在车身制造中的应用,对比分析电机驱动伺服焊枪(简称"伺服焊枪")与气动焊枪的电极力控制特性。结果表明,伺服焊枪接触工件时电极所受冲击力小,达到预压力时间短,焊接阶段的电极力波动较小,具有更精确的电极力控制能力。在此基础上进行伺服焊枪和气动焊枪点焊的电极磨损实验,进一步分析电极力变化对电极磨损的影响。结果表明,在完全相同的焊接条件下,由于伺服焊枪良好的电极力控制特性,其电极磨损速率较低。在整个电极磨损周期,伺服焊枪点焊镀锌钢板的轴向磨损随着电极力的增加而增加,但在磨损初期阶段,由于飞溅和点蚀的影响,较小电极力下的轴向磨损反而更大一些。 相似文献
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《Science & Technology of Welding & Joining》2013,18(7):671-678
AbstractSingle sided resistance spot welding (SSRSW) is considered as a feasible method to join hydroformed or closed section parts to others in vehicle productions. Unfortunately, it is difficult to guarantee the weld quality utilising conventional air gun. Because of a lack of support inside the closed section parts, the impact of electrode driven by pneumatic gun will cause large deformation of the workpieces at the welding stage and will lead to a crack around weld region after welding completion. In addition, poor weldability is another pressing problem for welding operations. Servo gun with new gun driven method has some merits such as realising the soft touch between electrode and workpieces and changing electrode force during the welding process which are greatly suitable to the sheet to tube joining. Based on the characteristics of servo gun, the present paper investigates a new method to increase the weld quality of sheet to tube joining with SSRSW method. By adjusting the electrode force during the welding process, weld strength would be increased, weld deformation be decreased and weldability lobe curve be widened. The results verify that servo guns can provide high assurance for welding quality of sheet to tube joining and have broad prospect in SSRSW. 相似文献
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通过建立轴对称有限元模型,对管板单边电阻点焊预压过程中电极与板以及板与管间接触行为进行了研究,系统分析了预压阶段接触区域范围及接触压力分布的影响因素.研究发现,管板焊接过程预压阶段的接触压力分布与传统点焊过程预压阶段接触压力分布有很大的不同.在电极和板以及板和管之间均形成环状接触区,可能导致焊后形成环状熔核;预压过程中,电极和板间接触区不受压力变化影响,板和管间接触区则受压力影响明显;接触区域大小和电极端面直径、管板厚度等因素均有关系.试验表明,所建模型的模拟结果与实际是相吻合的,为今后管板电阻点焊工艺参数优化及车身轻量化中管板厚度比优化提供有效依据. 相似文献
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镀锌钢板电阻点焊时由于锌层的影响电极损耗非常严重。以厚0.8mm家电用热镀纯锌钢板DX51D+Z为研究对象,探究在正交试验优化焊接参数后,热镀锌钢连续点焊时焊接接头质量变化的规律和电极损耗的特点。结果表明,当采用I=11 kA、P=2 500 N、T=13 cyc的点焊工艺参数组合可获得力学性能最佳的点焊接头;连续点焊试验初期(150点前)焊点力学强度稳定且焊点成形较好,焊接后期(150~300点)接头力学强度波动大,焊接状况不稳定;电极损耗至失效是接头质量急剧下降的主要原因,电极失效形式为头部塑性变形、端面坑蚀和Cu-Zn合金化,在本试验条件下,Cr-Zr-Cu电极焊至150点后显现不稳定现象,电极寿命约280点;失效电极端面的Cu-Zn合金层约65μm。 相似文献
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《Science & Technology of Welding & Joining》2013,18(2):140-145
AbstractElectrode displacement has been used to monitor resistance spot weld quality for long, but the fluctuation of the electrode displacement has not been well studied. This paper analysed the mechanism of the displacement fluctuation by collecting the welding current and electrode displacement during welding process and extracted the incremental pulse expansion of the electrode displacement, which was named as the displacement fluctuation peak. Through metallurgical experiments, the relationship of the displacement fluctuation peak with the weld nugget growth during resistance spot welding process was analysed. The whole process can be divided into four successive stages, and five characteristic points of the displacement fluctuation peak curve were selected to online predict the weld quality. The variation in the displacement fluctuation peak curve under different welding currents was studied, and the results showed that the displacement fluctuation characteristics can be used to effectively evaluate the weld quality. 相似文献
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《Science & Technology of Welding & Joining》2013,18(5):294-298
AbstractA new method for rapid and accurate acquisition of the shape of an electrode indentation in a workpiece during resistance spot welding (RSW) is presented. The method is based on illumination of the indentation with structured laser light and detection of the image of the illuminated object using a charge coupled device camera. The image from the camera is digitised using a frame grabber and fed into a personal computer where it is processed and analysed. This paper presents the basic principles of the method and discusses the image processing algorithms developed to measure the indentation shape characteristics, such as diameter, depth, and volume. Results from an application of the method to study electrode wear during RSW of zinc coated steel are also presented. 相似文献
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基于ANSYS有限元分析软件,对电极端面为矩形的电阻点焊温度场进行数值模拟研究.在综合考虑模拟精度和具体工艺条件的基础上,对物理模型进行适当的简化处理,建立了矩形端面电极电阻点焊温度场1/4三维有限元分析模型,接触电阻采用电阻率的形式进行处理.结果表明,在焊接初期电极压力在电极端面边缘形成较大的应力分布,使得最高温度分布在电极边缘区域,随着焊接时间增加,接触电阻减小,最高温度向内部转移形成熔核,此时与传统点焊情况相似. 相似文献
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研究了表面处理对微型点焊镀镍钢板和镍板时电极失效的影响.结果表明:微型点焊镀镍钢板和镍板时电极的失效主要是电极头部的塑性变形以及电极和镀镍板之间局部焊接的断裂发生在电极表面而导致的电极磨损;表面涂敷TiC的CuCrZr电极的寿命(1 200点)是CuCrZr电极寿命(600点)的两倍,表面处理能提高电极寿命的主要原因是表面涂敷的TiC颗粒能阻碍电极和镀镍板之间的局部焊接,以及减小电极表面的塑性变形. 相似文献