本文主要介绍了LG-500型、引孤频率选为20～60仟赫的等离子孤切割机设计、研制的过程。经过反复调整和大量的工艺试验,该机达到了引弧可靠,性能稳定、调节容易、使用方便、节省材料、解决土产难关的目的。 该设备设计、研制的突出特点有以下两个主面: 第一:将引弧振荡器的振荡频率设计为20～60仟赫,此频率与国内同类引弧振荡器频率150～260仟赫降低约8倍左右。实践证明,引弧频率在150～260仟赫时存在的问题有①频率越高,产生高频电磁场越强,对操作者身体越有害。频率150-260仟赫的振荡器,引弧时产生的高频电磁场达15～24伏/米,而频率20～60仟赫振荡器引弧时高频电磁场只有3伏/米;②频率越高,对设备中电器元件干扰越严重,电器元件表面发热,甚至会造成可控硅误导通,电压表失灵;③频率越高,对针钨极烧损严重,频率太高引弧反而不理想。引弧频率选为20～60仟赫,避免了引弧频率在150～260仟赫出现的弊病。 第二:设计切割电控程序时,将等离子小弧转移成大弧增加一段交错时间,国内同类产品都没有小弧转移大弧的交错时间。增加这段交错时间的好处在交错时间里小弧给大弧以充分子热,使离子气很快达到高度的电离;①小弧转移大弧不发生突变,避免了切割电弧不稳或断弧观象。这段交错时间2-5秒即可。 应用该切割机切割 This article mainly introduces the design and development of the LG-500 plasma cutting machine with a frequency of 20-60 kilohertz. After repeated adjustments and a large number of process tests, the aircraft reached a reliable arc, stable performance, easy regulation, easy to use, save materials, to solve the purpose of the difficulties of indigenous products. The device design, development of the outstanding features of the following two main surfaces: First: the oscillation frequency of the arc ignition oscillator designed for 20 to 60 kHz, this frequency and the same type of low-frequency oscillator frequency of 150-260 kHz About 8 times. Practice has proved that the arc frequency of 150 to 260 kHz when there are problems ① higher frequency, resulting in high-frequency electromagnetic field is stronger, the more harmful to the operator’s body. Frequency 150-260 kHz oscillator, high-frequency electromagnetic field generated when the arc reached 15 ~ 24 volts / m, while the frequency of 20 ~ 60 kHz oscillator arc high-frequency electromagnetic field only 3 V / m; ② frequency High, the more serious interference on the electrical components in the device, the surface heating of electrical components, SCR may even lead to false turn-on, the voltage meter failure; ③ The higher the frequency of tungsten burning on the needle very serious, too high frequency arc is not ideal . Select the arc frequency of 20 to 60 kilohertz, to avoid the shortcomings of the arc frequency of 150 to 260 kHz. Second: Design cutting electronic control program, the plasma arc into a large arc to increase a period of staggered time, the domestic similar products are no small arc transfer arc interlacing time. Increase the benefits of this staggered time in the staggered time to a large arc to small arc enough sub-heat, so that the ionization gas to achieve a high degree of ionization; ① small arc transfer arc does not change suddenly, to avoid cutting arc instability or broken arc Observatory. This staggered time 2-5 seconds can be. Use this cutter to cut