共查询到18条相似文献,搜索用时 62 毫秒
1.
随流孕育目的在于防止孕育剂衰退所引起的铸件废品。随流孕育时不仅要求孕育剂流量稳定,也希望铁液流量稳定,以保证两片比值稳定,从而效果好而用量省。扇形浇包无论是径向出铁(图1a)和轴向出铁(图1b)其出铁口都在扇心上,在倾转浇注时。其出铁量△V与转角△T的比值C为常数,似乎每次转角一定,出铁量就一定。但由于包腔内存在挡渣板和包腔两侧斜度,上述关系成为变数。为保证C值仍然为常数,必须对浇包内腔曲 相似文献
2.
盂繁玉 《中国铸造装备与技术》1989,(2)
锥筒形浇包的转轴位置对其使用性能关系重大。作者用微机对我国已有的三种计算公式进行了运算,结果证明三种计算方法均正确。作者分别按最大操作力矩最小和倾注过程中作功最小为目标进行了优化设计计算,所得最佳转轴位置相差甚微,故两种方法均可在工程上应用。 相似文献
3.
当使用常规的容积大于金属液体积的锥筒形浇包浇铸时,开始有一段不出金属液的空转角,通常金属液体积为浇包容积的85%时就会有20%的金属液留在后面的转角中.这个情况对以锥筒形浇包为基础的等流浇铸技术的实施大有影响.因而必须对常用的余液体积和体心矩计算方法作必要的补充改进。用新的计算方法编制的电算文件ZLVXY3取得了一系列可靠的数据。 相似文献
4.
5.
6.
在建立任意锥体体积与重心通用计算式的基础上,导出了普通锥筒形倾转浇包和几种常用特型浇包余留金属液体积与重心的通用计算公式。 相似文献
7.
8.
9.
我厂生产的球墨铸铁件主要是阀盖和手轮,随着产品的提挡升级,对表面质量和内在质量的要求越来越高,特别是铸件经抛丸处理后,表面缺陷就充分暴露出来,尤其是表面夹渣缺陷,按老工艺浇出的铸件合格率仅15~20%,通过对浇注系统进行改进,成功地消除了夹渣缺陷。 相似文献
10.
在介绍国内随流孕育及浇注机应用情况的基础上,叙述了所研制的能够实现随流孕育及等流量浇注的液压式自动浇注机的技术参数、特点及实现方法。 相似文献
11.
12.
13.
Today more and more cars are produced every year. All of them have to be equipped with catalytic converters, the main role of which is to obtain substances harmless to the environment instead of exhausted gases. Catalytic converters contain platinum group metals (PGM) especially platinum, palladium and rhodium. The price of these metals and their increasing demand are the reasons why today it is necessary to recycle used auto catalytic converters. There are many available methods of recovering PGM metals from them, especially platinum. These methods used mainly hydrometallurgical processes; however pyrometallurgical ones become more and more popular. The article presents results of the research mainly concerning pyrometallurgical processes. Two groups of research were carried out. In the first one different metals such as lead, magnesium and copper were used as a metal collector. During the tests, platinum went to those metals forming an alloy. In other research metal vapours were blown through catalytic converter carrier (grinded or whole). In the tests metals such as calcium, magnesium, cadmium and zinc were applied. As a result white or grey powder (metal plus platinum) was obtained. The tables present results of the research. Processing parameters and conclusions are also shown. To compare efficiency of pyrometallurgical and hydrometallurgical methods catalytic converter carrier and samples of copper with platinum obtained from pyrometallurgical method were solved in aqua regia, mixture of aqua regia and fluoric acid. 相似文献
14.
This paper describes the application of a biomimetic search method to develop Ideas for centering objects in microassembly. Biomimetics involves the imitation of biological phenomena to solve problems. An obstacle to the use of biomimetics in engineering is knowledge of biological phenomena that are relevant to the problem at hand. The method described here starts with an engineering problem, and then systematically searches for analogous biological phenomena using functional keywords. This method is illustrated by finding and using analogies for the problem of positioning and centering objects during microassembly. Relevant phenomena identified Involve microtubule organizing centers, photosystems, and retinal ganglion cells. 相似文献
15.
16.
17.
叙述了用于真空电子束圆形焊缝的自动跟踪系统的设计和试验过程。在真空电子束焊接航天器件的圆形焊缝时 ,由于工装等原因 ,出现电子枪回转中心与焊缝圆心不同心现象。使用本控制系统 ,用小束流电子束先对焊缝进行扫描 ,利用电子束在焊缝上和在工件上反射回来的二次电子数量不同而反映出焊缝的位置 ,并由计算机实时记录整个圆形焊缝各点与束斑间的偏差值 ,完成一个示教过程 ;然后由计算机处理与分析所获取的数据并存储 ;在焊接时利用处理后的偏差值在圆形焊缝相应位置不断修正电子枪的位置 ,从而达到电子束斑点与焊缝对中的目的 相似文献
18.
铸造工厂由于生产过程复杂,影响因素多,在进行质量改善时,一个问题往往有多种原因,无法有针对性地采取对策。分层分析法可以使问题条理化,有助于抓住问题的实质,对于铸造工厂如何准确找到改善重点,是个有力的工具。 相似文献