共查询到20条相似文献,搜索用时 312 毫秒
1.
2.
3.
4.
研究了拉杆锻件的辊锻制坯技术,采用2道次体积分配辊锻模具和一次头部压形模具,得到拉杆锻件的坯料形状与尺寸。成功地解决了辊锻道次的确定和型槽系的选择,模具设计等问题。据此成果,完成了拉杆锻件的生产线。 相似文献
5.
6.
冷弯型钢在工业及建筑业有广泛的应用。本文以设计三轮车车圈成型辊孔型为例,论述了冷型型钢坯料宽度的计算公式,拟定成型方法,确定成型制度以及设计成型辊孔型等。 相似文献
7.
8.
为了适应生产的需要 ,武汉理工大学材料学院材料成形及控制工程系研制开发了双锥辊辗压机 ,并且申报了有关专利。重庆工学院张猛教授参与了双锥辊辗压机、工装设计及模具研制工作。双锥辊辗压机的两个锥辊分别安装在机器主轴轴线两侧。两锥形轧辊回转线与机器主轴轴线相交于一点 ,交角α =45° ,锥顶角 β =180°-2α。主电机减速箱驱动回转头旋转 ,实现两锥辊绕机器主轴轴线公转。工作台装在滑块上 ,在液压驱动下 ,工作台与锥形轧辊距离渐近 ,直到锥辊与工件接触时 ,两者之间的接触摩擦力带动锥辊绕自身轴线自转。滑块的继续运动形成锥辊对… 相似文献
9.
10.
在生产过程中,操作工经常会遇到这样的情况:设备正常运转一段时间后,"U"型刀及对应辊轮会产生不同程度磨损,当磨损量较大时,会产生透明纸"U"型拉线切割不完整或拉线切不断现象,导致透明纸在输送通道内歪斜、堵塞,影响设备的正常运转,不但增加了原辅材料消耗,而且加大了操作工的劳动强度,同时影响设备的有效作业率,更严重的是部分拉线切割质量差的条包可能会流入市场,对消费者的利益和企业形象造成影响。其主要是由于"U"型刀和对应辊磨损失效所造成,由于对应辊表面的硬度不是很高,并且"U"型刀总是在对应辊上同一点进行切割,对应辊在"U"型切刀的作用下切割部位磨损很快,正常使用的周期较短,需要经常调整和更换。但是维修过程中,维修人员发现"U"型刀和对应辊磨损比较快,使用周期短,一套国产备件中对应辊约为2-4个月,"U"型刀约为5个月,备件消耗大。此问题对产品质量、生产效率均造成了不同程度影响,针对这个现象我们决定对对应辊进行改进。 相似文献
11.
目的研究舰载系留气球在海洋环境下对系留缆绳以及球体姿态的影响。方法采用ADAMS二次开发宏命令来建立离散化系留缆绳模型,并将离散化系留缆绳几何模型在相邻微段圆柱间添加Bushing轴套力,设置相关刚性系数和阻尼系数获得完整特效的缆绳模型。同时根据船用起重机的相关设计规范,考虑船体横摇5°和纵摇2°等运动影响,分析船体运动情况可知,纵摇时系留缆绳下端系固点位置较之横摇波动幅度更大,对缆绳的影响更大,因此主要研究船体纵摇2°情况下对于系留缆绳的影响,并分析对比船体静止以及船体纵摇2°情况下对于舰载系留气球系留缆绳以及球体姿态的影响。结果获得了在船体静止状态以及纵摇激励影响下舰载系留气球系留缆绳张力变化曲线以及球体姿态变化曲线。船体纵摇2°情况时,系留缆绳在仿真开始阶段承受冲击载荷较大,峰值达到150 kN,随后缆绳载荷基本在25 k N上下浮动。张力变化曲线整体呈现周期变化,周期与船体纵摇周期一致,为10 s。球体横滚角和航向角变化与船体静止状下仿真结果基本一致,球体俯仰角变化幅度较大。结论船体纵摇时会对系留缆绳带来较大的冲击载荷,同时对球体的俯仰姿态产生影响。该仿真结果对舰载系留气球的可行性分析和适装性研究以及系留缆绳的选用具有较大的指导意义。 相似文献
12.
《Journal of Manufacturing Processes》2014,16(4):468-478
In the present study, a 2-D finite-element method (FEM) thermal-fluid-stress model has been developed and validated for the twin roll casting (TRC) of AZ31 magnesium alloy. The model was then used to quantify how the thermo-mechanical history experienced by the strip during TRC would change as the equipment was scaled up from a laboratory size (roll diameter = 355 mm) to a pilot scale (roll diameter = 600 mm) and to an industrial scale (roll diameter = 1150 mm) machine. The model predictions showed that the thermal history and solidification cooling rate experienced by the strip are not affected significantly by caster scale-up. However, the mechanical history experienced by the strip did change remarkably depending on the roll diameters. Casting with bigger rolls led to the development of higher stress levels at the strip surface. The roll separating force/mm width of strip was also predicted to increase significantly when the TRC was scaled to larger sizes. Using the model predicted results, the effect of both casting speed and roll diameter was integrated into an empirical equation to predict the exit temperature and the roll separating force for AZ31. Using this approach, a TRC process map was generated for AZ31 which included roll diameter and casting speed. 相似文献
13.
电路板因为具有韧性高、多组分的特性,在处理过程中不易被破碎。辊式破碎机具有结构简单、工作可靠、能耗低等特点,可用于废旧电路板的粗碎环节。该类辊式破碎机主要由电机、减速器、轴、齿辊、齿轮等组成,齿盘的齿牙形状、尺寸、排列可按电路板物料性质进行设计。首先通过设计计算并使用UG NX软件建立虚拟样机,分析了片状物料在破碎中受力情况;再使用Nastran模块对辊式破碎机的重要部件齿盘进行有限元分析,得出齿盘上承受载荷比较大的位置并对此提出了强化措施。 相似文献
14.
The deformation inhomogeneity of flat wires produced with roll drawing process is analyzed. The effect of main process parameters, i.e., initial wire diameter, forming roll dimension and thickness reduction on deformation inhomogeneity is established by means of experimental tests and a developed FE model. Vickers microhardness–strain relationship is developed for the analyzed material (low carbon steel AISI-1010) by correlating the microhardness measurements and effective strain fields as predicted by an axisymmetric numerical model of a compression test. A non-linear finite element model of roll drawing process is developed for a thorough understanding of process parameters effect on deformation inhomogeneity. Thus, in order to encompass the wide range of process conditions, an inhomogeneity index, calculated as the coefficient of variation of effective strain, is used. The numerical results showed that the inhomogeneity factor of flat wires produced with roll drawing is highly dependent on area reduction. 相似文献
15.
Choumad Ould Xavier Badiche Pierre Montmitonnet Yves Gachon 《Journal of Manufacturing Processes》2013,15(1):77-86
The cost of rolling is determined in particular by productivity and lifetime of rolls before regrinding. Adhesive wear of the sheet gives rise to transfer on the roll surface. Its occurrence depends on rolling conditions and is one of the determining factors of the maximal reduction for a given rolling speed. Abrasive wear of the roll is the second factor for roll lifetime. Both phenomena are strongly related to tribological and mechanical characteristics of the surface layer of rolls. Stainless steel is known for its high adhesiveness. Coatings with good tribological properties could help extend the roll service. In this paper, the potential of different PVD coatings (CrN, TiN and TiBN) is explored. The impact of these coatings on influential phenomena during rolling is analyzed thanks to well-adapted tribological and mechanical laboratory tests. The results show that TiN has a good potential in cold rolling of stainless steel strips. 相似文献
16.
17.
目的分析旋转尾翼对火箭测试平台平衡滚速的影响,基于旋转尾翼式火箭测试平台开展飞行弹道设计。方法以旋转尾翼火箭测试平台为例,分析旋转尾翼、箭体和滚动轴承间的受力,建立旋转尾翼火箭测试平台箭体和尾翼滚转通道动力学模型,分析旋转尾翼不对称性、不同摩擦力系数时旋转尾翼对平台箭体平衡滚速的影响关系,并以倾斜有轨发射旋转尾翼火箭测试平台为例,开展弹道设计与仿真。结果采用旋转尾翼设计,当滚转等效舵偏较大时,能够降低固定尾翼平台平衡滚转。随着滚转等效舵偏的增加,箭体的平衡滚速不会持续增加,箭体的平衡滚转速度将稳定在4.4 rad/s左右。旋转尾翼轴承摩擦力系数显著影响旋转尾翼对箭体平衡滚速的抑制作用。经过弹道设计仿真,箭体的平衡滚速为4.01rad/s,满足试验载荷对转速的需求。结论旋转尾翼能够有效抑制箭体的平衡滚速,基准弹道设计满足飞行试验要求。 相似文献
18.
孙峰 《安全.健康和环境》2021,21(1):38-41
沸腾液体膨胀蒸气爆炸(BLEVE)是反应失控常见的后果之一,针对常用的TNT法计算BLEVE爆炸超压效应可能导致错误的情况,采用TNT法与Baker-Tang爆炸曲线法分别对反应失控导致的BLEVE爆炸超压效应进行计算,并与现场证据相比较,考察不同模型计算的准确性。结果表明,TNT当量法计算的理论超压过高估计了实际超压。当估计碎片所占能量在32%~50%之间时,Baker-Tang爆炸曲线法计算的超压与实际爆炸超压吻合较好。因此,Baker-Tang爆炸曲线法是BLEVE爆炸超压预测的有效工具。 相似文献
19.