共查询到19条相似文献,搜索用时 125 毫秒
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提出了一种采用外特性自适应控制实现短路CO2焊电磁力与表面张力自均衡过渡方法。基于提出的缩颈过程液桥表面形态变化规律的简化模型,文中对不同液桥形态下表面张力性质进行了分析,考虑到熔池波动等因素对液桥形态的影响,单纯依靠表面张力过渡必然存在由于液桥不能及时爆断而引发的稳定性问题。在研究了电磁收缩力和液桥半径及短路电流的关系、液桥电阻和液桥半径的关系之后,设计了本文的方案。试验结果证明,此种方法不仅可以有效提高短路液桥缩颈过程中电流的衰减速度,减小短路液桥爆断前集聚的能量并达到减小飞溅的效果,同时又实现了电磁力与表面张力的自动均衡,确保了熔滴的平稳过渡和液桥的及时断开,有效改善了焊接过程的稳定性。 相似文献
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IGBTCO2焊波控焊机的研究 总被引:4,自引:0,他引:4
利用IGBT串接到ZD5型焊机回路中,使之在CO2焊短路过渡过程中工作用于开关状态,从而控制短路电流上升速度,控制金属液桥的爆断能量,达到对电流波形加以控制并减少飞溅的目的。 相似文献
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CO2短路过渡过程检测及应用 总被引:9,自引:0,他引:9
分析了CO2气体保护焊短路过渡飞溅产生的机理,阐述了导致飞溅产生的三个重要过程,即瞬时短路,液桥缩颈后爆断和重新燃时冲击熔池。提出了CO2短路过渡液桥状态检测的新方法,并介绍了液桥状态传感器系统的工作原理,组成及此方法在抑制短路电弧飞溅产生的新型工艺质量控制法中的应用,并取得了满意的工艺效果。 相似文献
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该文根据国家技术政策开发了一种具有CO2气保护焊和手弧焊两用功能的逆变电源,研究了CO2弧焊短路过渡过程的电流波形控制技术,用较简单的方案获得了较好的控制效果,对减少气溅和改善焊缝成型均有明显效果,但中等参数混合过滤态下飞溅仍较大。 相似文献
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IGBT逆变式波形控制CO2弧焊电源的研究 总被引:5,自引:2,他引:5
本文针对IGBT弧焊逆变器,提出并实现了适于短路过渡CO_2气体保护焊的输出波形控制方法。对焊接电弧参数实时采样以及工艺试验均表明,所研制的逆变式波控CO_2弧焊电源对减小金属飞溅和改善焊缝成型均有明显效果。 相似文献
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表面张力过渡(也称STT)是CO2气保焊中一种极低飞溅的过渡形式,它是基于熔滴过渡理论和电子化的焊接电源基础上发展起来的。该技术已应用于西气东输的管线打底焊接。作者在对CO2气保焊表面张力过渡理论研究的基础上,利用Matlab软件建立了电源-电弧非线性系统模型,和电流型逆变器系统模型,对表面张力过渡过程中的燃弧、短路等各个阶段进行了仿真,研究了燃弧阶段熔滴长大对弧长的影响,液桥分断阶段输出电感对电流下降率的影响。研究表明液桥分断时,输出电感的大小是控制飞溅量的关键条件。将仿真波形与实际波形相比较,二者基本吻合。 相似文献
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波形控制CO2弧焊逆变电源的研究 总被引:2,自引:0,他引:2
介绍了一种新型CO2弧焊逆变电源,本电源从电弧物理过程出发,运用表面张力过渡理论通过微机实时控制焊接电流波形,在进行短路过渡CO2焊接时能明显减少飞溅,同时改善焊缝成型。 相似文献
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A new current wave controlling method for short circuit transition CO2 welding using saturable inductor is put forward in this paper. Theory analysis and experiment results prove that the inverter's dynamic characteristics is greatly improved, the declining speed of current during liquid bridge neck shrinking is quicker, subsequently the energy accumulated in the bridge and the radius of the bridge before rupturing is reduced thus the low spatter result is achieved. 相似文献
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为了减少CO2气体保护短路过渡焊的飞溅,本文提出了短路过渡过程的闭环实时控制思想并进行了试验研究。在熔滴与熔池发生短路及液体小桥爆断这两个最容产生飞溅的时刻,利用大功率电子关元件切换焊接回路外串电阻的方法及时降低焊接回路中的电流。在前一时刻维持较低电流至溶滴与熔池充分接触,在后一时刻维持较低电流至熔滴过渡完毕,该方法能有效地抑制由瞬时短路造成的大颗粒飞溅和由电爆炸产生的细颗粒飞溅,实现了CO2气体保护焊短路过渡过程的闭环实时控制。 相似文献
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Pulsed MIG welding is suitable for aluminum alloys welding, because spray transfer and excellent profile can be arrived during whole welding current range, and the energy of droplet can be controlled to overcome losing of alloy elements with lower melting and steam point by controlling pulse current and pulse time. Because of the special physic properties of aluminum alloys, there are different requirements for pulsed MIG welding between starting arc short circuit and drop transfer short circuit, pulse period and base period. In order to satisfy the need of aluminum alloys MIG welding, self-adjusting dynamic characteristics are designed to output different dynamic characteristics in different welding startes. The self-adjusting dynamic characteristics of pulsed MIG welding are achieved through a short circuit controller and a dynamic electronic inductor. The welding machine(AL-MIG 350) with self-adjusting dynamic characteristics has a high rate of successfully starting arc up to 96%, and the short circuit time during transfer is less than 1ms, in the mean time, the arc is stiffness, spatter is low and weld appearance is good. 相似文献
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本文详细地分析了ZX5-400型可控硅手弧焊电源动特性的几个特点。认为这类焊机,由于从负载至短路过渡过程的电流上升时间短,因而用低氢型焊条焊接时,65%以上的熔滴,在短路过渡时所形成的小桥金属,破断发生在负载至短路动特性电流波形的下降段,甚至在隐态短路电流段。这样,对减小飞溅十分有利。同时提出考核这类焊机动特性的新方法。科学地论证i_(fd)/I_f(t_o)这(?)参数能准确反映电源动特性与飞溅的关系,对修正直流弧焊电源动特性标准有很大参考价值。 相似文献
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《Science & Technology of Welding & Joining》2013,18(8):708-716
AbstractIn non-pulsed gas metal arc welding (GMAW), spatter can be reduced by controlling the short circuit current to a low level just before the re-arcing. The controlled bridge transfer (CBT) process, which optimises the accuracy of predicting the re-arcing in real time in response to the metal transfer, realises stable, low spatter level. In this research, the methods for controlling short circuit transfers to minimise spatter and realise stable arcs in GMAW of stainless sheet using argon rich shielded gases are investigated. The new CBT process has been developed by applying the specific arc length estimation method that is not affected by abnormal rise in arc voltage. This process can suppress the spatter generation caused by a fluctuation in the vibratory motion of the weld pool or inaccurate prediction of the re-arcing in the succeeding short circuit/re-arcing cycle, and thereby spatter free GMAW in the short circuit transfer mode can be carried out even on stainless steels. 相似文献
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对于逆变弧焊电源,采用基于 DSP 的全数字控制策略.针对短路过渡 CO2 气体保护焊特点,提出了准恒压全数字化新型波形控制策略,不再根据输出电压区分短路和燃弧过程,使得短路和燃弧过程过渡自然,适应于所有的焊接工艺,提高了系统的适应性.同时在短路初期采用瞬态电流抑制技术减少了飞溅,建立了包含实时燃弧能量补充机制的全数字化电压电流瞬时反馈的全数字三闭环控制模型.结果表明,所提出的全数字化软开关控制策略灵活、可靠;所采用的数字波形控制技术适应性好、灵活、焊接过程稳定、焊缝成形优良.Abstract: According to the characteristics of short circuit transfer of CO2 gas metal arc welding, a novel full digital waveform control scheme called quasi-constant voltage control is presented for inverter type arc welding power based on DSP. Short circuit and arc ignition process are not judged according to the output voltage and transfer process between them is smooth. The strategy is also applied to all welding conditions. Initial current at the instant of short-circuit is suppressed to reduce spatter generation. A triple closed loop control model including real time energy compensation for the arc state based on instantaneous voltage and current feedback control is estabhshed. Flexibility and reliability of the proposed fully digitalized softswitching control strategy is validated by experimental results of 400 A welding machine. The experimental results show that proposed digital waveform control scheme is applicable for different wire feeding speed conditions, and the welding process is stable and the welding bead appearance is good. 相似文献