共查询到20条相似文献,搜索用时 140 毫秒
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叙述了摩托车铝输金车轮当前国内普遍采用的几种铸造工艺,从技术、产品质量、经济效益上分析和比较后认为,以液压开合模金属型得力浇铸单机为好。 相似文献
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传统烧结机台车轮自动注油系统注油量控制存在控制精度低和鲁棒性差等问题,已经无法满足精确注油的需求。为改善注油性能,提出一种基于改进灰狼(IGWO)算法的烧结机台车轮注油量智能控制方法。利用MATLAB软件辨识注油量控制系统数学模型;搭建BP神经网络PID注油量控制系统;为了提高灰狼算法的收敛速度,引入非线性收敛因子和动态权重,设计IGWO算法实现对BP神经网络的最优初始值及阈值的寻优,输出最优PID控制参数;最后,在仿真环境下,将用IGWO算法优化前后的控制效果进行对比。结果表明:所设计的PID控制器超调小、控制精度高,能够实现注油量的智能控制,满足精确注油的需求。 相似文献
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介绍了一种外壁带凸台锥形截面环件的一体成形轧制工艺,该工艺降低了外壁带凸台锥形截面环件的材料消耗,提高了环件的整体质量。通过ABAQUS软件建立了该环件轧制成形的有限元模型,并对轧制成形工艺进行了分析,研究了轧制过程中Mises应力、内壁位移和等效应变的变化规律。结果表明:在环轧开始阶段,由于应力分布不均匀,应力呈周期性变化,在4.5 s后,环件的应力分布逐渐均匀;在材料填充凸台过程中,远离凸台孔处的材料堆积并高于凸台孔;凸台两侧的应变存在差异,且当进给量为4.5 mm时更加明显。实验结果与模拟结果相近,验证了该成形工艺的可行性。 相似文献
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我厂为宝钢生产的车轮是钢水罐车和卸船机上的重要零件,采用优质轧辊钢60CrMnMo制造。最初用调质和整体加热淬火,基本满足了车轮的技术要求。为了进一步降低生产成本,提高了生产率,我厂进行了工艺改进,取得了好的效果。l车轮用钢的化学成分和热处理要求60CrMnMo钢(按EZB553-84标准)的成分范围(%)为0.55~0.65C,0.20~0.60Si,0.70~1.0Mn,0.8~1.20Cr,0.25~0.40Mo,≤0.30P,≤0.30S,热处理后的力学性能要求如表1所示。2改进的车轮热处理工艺(1)减少了工序改进前车轮的生产流程是:冶炼→锻造→粗加工… 相似文献
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本文较详细介绍了白银铝厂电解AC多功能天车小车传动系统及绝缘方式的改造原因,改造方案,及其改造两年后的使用效果。 相似文献
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A nondestructive inspection technique, based on stress-induced magnetic anisotropy, provides a means of quantifying the residual stress distribution in railway wheels. An automatic prototype device has been constructed; calibration measurements were carried out to examine the sensitivity of the technique to metallurgical effects in the wheel grades of interest. The device was used to obtain residual stress information on new and thermally damaged wheels representing a range of service conditions. The validity of the technique is examined using additional strain gauge measurements. A relationship is established between the output of the device and net circumferential stress within the wheel rim. 相似文献
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声光调QNd:YAG脉冲激光修锐金属结合剂金刚石砂轮 总被引:1,自引:0,他引:1
金属结合剂金刚石砂轮具有良好的磨削性能,在初次使用和磨损后必须对其修锐。由于金属结合剂和金刚石磨粒之间存在热物理、光学性质差异,可通过选择合理的脉冲激光功率密度去除结合剂,凸出磨粒,实现选择性去除。本文采用声光调QNd:YAG脉冲激光径向辐射,对金属结合剂金刚石砂轮进行修锐试验研究,并与传统机械修锐和连续激光修锐进行了比较。理论分析了声光调Q脉冲激光修锐金属结合剂金刚石砂轮的机理,试验研究了单脉冲激光烧蚀凹坑和脉冲激光修锐的情况,总结出激光、工艺参数对修锐效果的影响特点和规律。激光平均功率(Pm)增加、脉冲重复频率(f)减小、离焦量(Z)减小,则脉冲功率密度增加,凹坑深度增加。在本试验条件下,选择Pm=10W、f=5—8kHz、Z=0.0mm;Pm=20W、f=1—2kHz、Z=1.5mm和Pm=30W、f=1-2kHz、Z=3.0mm这些参数修锐,能获得较好的地形地貌。试验证明,以单脉冲试验为指导,合理选择激光参数进行修锐,可以得到较好的地形地貌。 相似文献
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针对火车轮内部缺陷,提出了一种基于地磁场环境下的无损检测方法。首先理论分析微磁检测应用于火车轮轮对内部缺陷的可行性,然后根据火车轮外观尺寸设计火车轮微磁检测系统,最后通过检测预制人工孔洞缺陷的火车轮试块完成微磁检测的试验部分。研究采用阈值法处理磁梯度检测信号,数据分析结果验证微磁检测对火车轮内部缺陷检测的可行性。试验结果表明:试件中孔洞缺陷直径一定时,埋藏深度越深,缺陷引起的磁感应强度相对变化量越小,而当孔洞缺陷埋深一定时,孔洞缺陷直径越大,缺陷引起的磁感应强度相对变化量也同样会越小,但磁场的异常区域越大;采用阈值法可有效识别缺陷,并实现缺陷微磁检测的可视化。 相似文献
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Grinding tools like one side recessed grinding wheels are used in many machining applications and must provide a high reliability
against fracture concerning safety-relevant and economic aspects. The calculation of the bursting speed on the basis of the
mechanical properties is an important tool for the design of grinding wheels. However, no equation is available to estimate
the bursting speed of these types of grinding tools so far. For the calculation of the bursting speed of one side recessed
grinding wheels a parametric study using FEA was carried out. The results of these investigations provide the basis for a
geometric function, which allows in association with a newly-developed fracture criteria to calculate the bursting speed of
one side recessed grinding wheels. For the validation of the developed concept spin burst tests with grinding wheels of eight
different geometries and two granulations were carried out. The results of these investigations show a very good correlation
of the calculated and measured bursting speeds for all tested types of grinding wheels. 相似文献
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针对欧洲高速动车使用的DB920车轮进行了工艺实验和实验室实验。结果表明,DB920车轮轮辋部位组织主要为少量铁素体和细珠光体,当组织中的铁素体比例较高且呈网状分布时,在进行断裂韧性评价实验时易出现撕裂状断口,在撕裂带侧面有大量韧窝,断裂韧性值(KQ)较高;相反,当铁素体比例较低时,断面相对平整,断裂方式以沿晶断裂和解理断裂为主,断裂韧性较差。组织分析和有限元模拟分析结果表明:喷水冷却时,轮辋处的冷却速度自踏面向内不断降低,冷速越慢,相变后生成铁素体比例就越高,断裂韧性也就越好。结合连续冷却实验的结果估算,对此成分车轮钢而言,当冷速大于1℃/s时,相变后不能获得足够的铁素体以保证此区域的断裂韧性。 相似文献
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Slotted diamond wheel grinding is a new machining technology. In this paper, an experimental study on the cutting force and the grinding temperature for ceramic face grinding using slotted diamond wheels is presented. Moreover, the empirical relationships related with the material removal rate, the surface roughness, the depth of cut, the wheel speed and the grain size are discussed. With these relationships, a temperature field for face grinding has been built. The work contributes to the fundamental theories for optimal design of slotted diamond wheels. 相似文献
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单层高温钎焊超硬磨料砂轮具有传统电镀砂轮无法比拟的优异磨削性能 ,国内应及早研制开发应用此种砂轮。本文利用真空炉中钎焊的方法 ,用Ni Cr合金钎料 ,适当控制钎焊温度、保温时间和冷却速度 ,实现了金刚石与钢基体间的高强度连接。扫描电镜X射线能谱 ,结合金相及试样逐层的X射线结构分析 ,剖析了Ni Cr合金与金刚石和钢基体钎焊界面的微区组织结构 ;揭示了Ni Cr合金对金刚石和钢基体表面的浸润和钎焊机理。即在钎焊过程中会在金刚石界面形成富Cr层并与金刚石表面的C元素反应生成Cr7C3,在钢基体结合界面上Ni Cr合金和钢基体中的元素相互扩散形成冶金结合 ,这是实现合金层与金刚石和钢基体都有高结合强度的主要因素。最后重负荷磨削试验表明金刚石为正常磨损 ,没有整颗金刚石脱落 ,说明金刚石确有高的把持强度 相似文献
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A multiple supplier tool management system based on reliable tool delivery forecasting is developed for optimum tool inventory sizing. The system is built up on the basis of historical data on tool management comprising the series of tool shipment and delivery dates between one manufacturing company and several external tool manufacturers in a supply network. If historical data are highly variable due to the incidence of uncertain but not random factors, classical time series analysis cannot measure the Imprecision deriving from events that are neither stochastic nor casual. An alternative is given by the analysis through intelligent computing techniques capable to deal with deterministic events but also take into account unpredictable factors for better results in prediction and forecast. A neuro-fuzzy system is used in this paper to approach optimum tool inventory sizing of CBN grinding wheels for nickel base alloy turbine blade fabrication. 相似文献
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采用空间占位法和固态粒子烧结法制备具有蜂窝状结构的超细粒度的陶瓷结合剂金刚石砂轮。通过考察砂轮的微观形貌、气孔率和抗折强度等性能,研究烧结制度对制备砂轮蜂窝状结构的影响。结果表明:制备具有蜂窝状结构的砂轮的最佳烧结温度为750 ℃,保温时间为90 min,得到的砂轮的孔隙率约为78%,抗折强度约15 MPa。 相似文献