Cumulative current‐magnetizing method for a capacitor‐discharged impulse magnetizer

This paper presents a cumulative current‐magnetizing method for magnetization of permanent magnet, aimed at alleviating the bulky capacitor problem of traditional capacitor‐discharged impulse magnetizers. The method employs circuit resonance to boost the output voltage. The resonant alternative current (ac) voltage is then directly discharged to the magnetizing coil without using any rectifier. The proposed resonant ac discharge repeats a number of times over several milliseconds. This allows the magnetizing current to increase incrementally until it reaches the peak that is sufficient to fully magnetize the permanent magnet. With this design, the energy for magnetization is accumulated by small steps, and each increment would require much lower energy. This results in smaller capacitors needed compared to traditional designs. To validate the effectiveness of the proposed scheme, several pieces of ferrite magnet without being pre‐magnetized were tested using the developed magnetizer. The test results support the feasibility and practicability of the scheme for potential applications. Copyright © 2017 John Wiley & Sons, Ltd.     

Consideration of multi‐coil type magnetization system for magnetic particle testing of omnidirectional crack in all surfaces of 3D shape test object

Mechanical parts, plants, and cross‐linkages inspected with magnetic‐particle testing (MT) are typically complex 3D shapes. In complex 3D shape portions, because a magnetizer often cannot be configured to inspection portions and the test object cannot be appropriately magnetized, there is a possibility of overlooking a crack in such an instance. Thus, MT system development that was successfully able to detect omnidirectional cracks in 3D shape portions was considered in this study's trials. Two multi‐coil type magnetizers were hence arranged face‐to‐face, and the magnetization of omnidirectional scenarios for all surfaces of 3D shape test object was evaluated.     

国内充磁机的发展状况及整体充磁机的主要技术问题

本文在广泛调研的基础上，综述了国内充磁机的发展状况，分析了我国研制开发整体充磁机需要解决的主要技术问题。     

机床零件用感应器的设计及选用

以几种典型的机床零件的感应加热淬火方式为例,分析了感应器的设计和选用,包括加热不同零件或零件特殊部位的施感导体即感应圈的结构及其加热效果,感应圈匝数选定,功率核算,仿形感应器,导磁体的应用等。     

超微晶合金旋转磁特性测量用励磁装置的设计与优化

旋转磁心损耗广泛存在于高频变压器T形连接点处与高速电机的定子上。为了对二者进行更好的分析,需要将高频下的旋转磁心损耗进行精确测量。本文就四种不同的励磁结构进行有限元分析,阐述了励磁结构对准确度的影响。在此基础上,根据超微晶物理特性提出一种立体式二维高频励磁装置,对励磁绕组进行计算,并优化设计了磁轭结构,将测试频率提高到10k Hz。     

导磁体替代硅钢片在感应加热中的应用

对带Fluxtrol LRM导磁体和硅钢片的典型感应器用20 kHz感应加热设备进行了感应加热试验,测定了这两种导磁材料的聚磁性和导热性能。结果表明,对于中低频感应加热,Fluxtrol LRM导磁体具有更好的聚磁性和导热性能,可以代替硅钢片。此外,还介绍了导磁体的某些应用实例。     

导磁体在感应加热中的应用

感应加热技术在金属加工、热处理等领域已得到了广泛应用。在感应加热中,导磁体的应用能显著提高感应器的加热效率、提高产品质量、节能等。目前,国内外可加工导磁体的研究与发展,为感应加热技术的进一步发展创造了有利的条件。与国外相比,我国导磁体还存在着一些不足,有待深入研究。     

用磁化水造球提高生球强度的研究

对包钢人玩氟精矿用磁化水造球，可使混合料成球性能及生球抗压强度，落下强度均显著提高，试验结果表明，合理的磁水结构为三次反向磁化器，水的最佳磁化流速为１５～３０ｃｍ／ｓ。     

大功率、大口径铜棒工频感应加热炉

合理选用大功率、大口径铜棒工频感应加热炉设计方案及对三相感应器与单相感应器的分析与比较。     

同步电机系统调试

本文以贵铝技改工程110kV空压站的LCN-3电脑型同步电动机可控硅励磁装置安装、调试的实践为例,重点阐述了电脑型同步电动机的工作原理、励磁装置的整定和数据,以及系统调试方法。