【作者】 蔡春梅；

【导师】 许澍华；

【作者基本信息】 北京化工大学 ， 机械设计及理论， 2006， 硕士

【摘要】 磁性塑料的传统制造工艺是铸造和粉末冶金,这些工艺的生产率低、生产成本高。磁性材料的注射成型就是为了克服传统制造工艺的上述缺点的,它是在塑料注射成型基础上发展起来的一种新工艺。采用塑料注射成型工艺生产的塑料永磁体与传统的烧结永磁体相比,具有工艺简单、生产效率高、能耗小、成本低等特点,因此具有广阔的市场和发展前景。磁性塑料注射成形技术可以较好地解决钕铁硼磁性材料的难加工问题,直接制备出具有最终形状的磁体,目前该技术己受到世界发达国家的高度重视,其发展及产业化速度非常快,而目前我国粘结磁体的生产,无论是设备还是原料在很大程度上还需依靠进口。鉴于上述的原因,本文对磁性塑料注射成型的关键设备及成型工艺进行了深入和系统的研究,提出了磁性塑料注射成型机的设计原则,并确定了SZC200/1000磁性塑料注射成型机的设计方案及主要技术参数,完成了整套注射装置的工程设计和成型模具充磁装置的工作图。另外,为建立饱和取向磁场强度,提高注射充模过程中各向异性磁体的取向度,文中从分析磁性材料的磁化机理入手,根据麦克斯韦电磁理论,在对模具磁路结构的磁导进行分析、简化的基础上,利用磁势方程推导出计算注塑模具磁路中磁场强度和磁势的公式。文中还讨论了脉冲充磁的充放电回路参数R,L,C与充电电压之间的关系,对模具磁路的设计具有重要指导意义。更多还原

【Abstract】 The traditional methods of manufacture plastic magnet are foundry and power metallurgy, with the disadvantages of low productivity and high produce income. In order to overcome the above disadvantages, the injection molding method of magnetic material appeared. Compared with the traditional method, the plastic permanent magnet has a wider application and good developing prospect with its simplified processing, high efficiency and low cost. Plastic magnetic injection molding technique may not only manufacture the final shape magnet directly, but also resolve the processing problem of NdFeB magnetic materials perfectly. At present, this technique has caught many advanced nation’s eyes around the world, so its development and industrialization are very quickly. Nowadays not only raw material but also manufacturing facilities of bonded magnets of China depend on importation to a great extent.In this paper, based on the reference of a mass of literatures, the work principle of a plastic magnet injection molding machine is analyzed, the design principle is presented. Meantime, the design project, key parameters of the main parts are given.In order to further improve the performance of anisotropic plastic magnet in the injection molding, the principle of magnetizing course on plastic magnetic materials is studied in this paper, and a calculation about the magnetic field system in the mould has been made on the bases of Maxwell electromagnetic thesis. The rule that the electric-current varies with the time is investigated. As a result, the optimum conditions which have a great value to practical production are found through the studies on the relationship between the parameters of R, L, C and U in the circuit.更多还原