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汽车顶棚是现代汽车内部装饰不可或缺的构成部分,同时具备功能性能、装饰性两大特点。随着人们在汽车方面的需求日渐多样化,在汽车发展过程中,汽车顶棚工艺的重要性持续提升。因此,本文从不同角度入手客观阐述了汽车顶棚及其总成的生产工艺,在优化生产工艺的基础上全面提升汽车顶棚的功能性以及装饰性。 相似文献
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齐瑞晓 《机械制造与自动化》2020,49(4):78-80
针对某MPV车型传动轴在加速过程中出现异响的问题,通过试验发现是由于花键配合间隙较大造成传动轴异响,故对传动轴主要技术指标进行校核。运用LMS Test.lab测试软件进行模态分析,最终分析结果与测试状态一致,为同类车型传动轴设计提供了参考。 相似文献
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利用铸铁的回弹性,采取一种工艺措施,设计出了圆柱体表面配合间隙的调节装置.用于超高速(42000r/min)电主轴套筒上,改善了系统的动态特性,使振动噪声降低了14.4%. 相似文献
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在一些机械传动的产品如汽车、工程机械中,变速器是重要的变速及传动部件。变速器中花键轴(下文简称外花键)和齿轮上的花键孔(下文简称内花键)多采用大径定心的配合方式。采用此种配合方式的缺点是:由于内花键大径通常在淬火处理前加工完成,在淬火后无法对内花键大径进行修整;由于热处理存在变形,造成内花键孔精度难以保证,容易导致在装配过程中内、外花键出现较大的配合间隙,变速器在工作时,由于负载和速度变化较大,配合间隙就会产生较大的冲击噪声。 相似文献
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李晓沛 《机械工人(冷加工)》2000,(9):43-45
4.配合的选择方法 选择、确定配合一般有以下三种方法: (1)类比法 根据设计的零件使用情况,参照同类机器已有配合的经验资料确定配合。这种方法的基本点是:统计调查、研究分析对比。按类比法选择配合,不应简单地搬用。 (2)计算法 根据零件的材料、结构和功能要求,按照一定的理论公式的计算结果选择配合。当用计算法选择配合时,关键是确定所需的极限间隙 相似文献
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装配特征之间的变动解析是产品装配偏差累积分析的重要基础,针对现有研究成果未考虑零件间装配特征定位顺序对配合间隙影响的问题,提出一种定位优先级约束下间隙配合的变动解析模型与装配成功率计算方法。建立了两个零件之间多基准装配的数学模型,并分析装配特征在配合前相对于装配名义位置的变动。通过对平行平面配合、圆柱面配合、圆锥面配合以及球面配合等四类间隙配合的接触状态进行分析,得到装配基准特征与装配目标特征在配合后相对装配名义位置变动所需满足的约束条件。在此基础上提出定位优先级约束下的装配特征之间的配合变动算法,并给出包含多组装配特征配合的两零件之间的装配成功率的计算方法。以一种测量仪器结构的装配为实例,验证了上述方法的可行性。 相似文献
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对于液压滑阀,泄漏和卡紧相互矛盾,与阀体阀芯的配合间隙密切相关。配合间隙过大,泄漏量大,降低或丧失阀的控制功能;配合间隙过小,阀体和阀芯在压力、温度的作用下变形,极易导致阀芯卡死,使阀突然失效;因此合理设计液压滑阀的配合间隙是滑阀研制成功的关键。本文利用ANSYS Workbench Environment平台,建立某大通径二位四通液动换向滑阀的三维有限元模型,采用热-结构耦合的方法,详细研究了阀体阀芯配合间隙随压力、温度及阀体壁厚变化的规律;结合材料及工况条件,对初始配合间隙和阀体壁厚进行了优化设计,在保证阀体强度、避免阀芯卡死的前提下大大降低了泄漏损失,并设计制造出样机进行试验研究,验证了优化设计结果。该优化设计方法对同类大通径滑阀的设计研发具有一定的参考价值。 相似文献
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运用六点定位原则,分析在MPV车桥实际生产中利用双短V型块限定工件的自由度,使工件在批量加工过程中准确占据定位元件所规定的位置,并对工件进行受力平衡分析,计算所受的切削力大小,由此估算工件加工时所需的夹紧力,选择合适的夹紧机构,以保证生产顺利进行。 相似文献
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为研究生鲜电商企业与配送企业,以及消费者组成的存在退货且有退货期限的冷链宅配供应链协调问题,讨论了集中决策和分散决策下的退货期限、销售价格、新鲜度、保鲜努力程度、收费策略以及最优利润。研究发现,利润最大化时,集中式决策允许更长的退货期限;当退货期限达到某一数值后,提高退货期限会使配送企业的利润减少,致使其没有动力提供对应的保鲜水平。通过设计组合契约协调发现,在配送企业的收费策略满足一定条件时,可以实现帕累托最优,调整契约分摊系数可以实现利润在生鲜电商企业与配送企业间的不同分配。 相似文献
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C. T. Pan C. C. Hsieh C. Y. Su Z. S. Liu 《The International Journal of Advanced Manufacturing Technology》2008,39(11-12):1071-1079
The trend towards using a large area of thin-film transistor liquid crystal display (TFT-LCD) glass substrate introduces challenges for cutting quality and production yield. For the requirements of boosting manufacturing efficiency and reducing cost, the optimization of cutting parameters becomes very important. In this study, we use a cutting wheel to directly scribe the glass substrate so as to generate a cutting score depth of the glass. The glass is then cleaved utilizing the principles of mechanical stress. We investigate quality issues such as median crack, lateral crack, cutting score, and cleaved profile with respect to different cutting pressures and wheel depths, which are in the ranges of 0.16 to 0.24 MPa and 0.1 to 0.3 mm, respectively, with a cutting speed of 350 mm/s. The glass substrate for the experiment is Corning EAGLE 2000 with a thickness of 0.7 mm. It is found that the median and lateral crack length can reach 140 and 403 μm, respectively, when the cutting pressure increases to 0.24 MPa. 相似文献
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Correlation between the surface quality and the abrasive grains wear in optical glass lapping 总被引:1,自引:0,他引:1
The subject of this study is to determine the relation between the optical glass surface quality and the wear of abrasive grains used in finishing process. The glass surface quality was characterized by the roughness (rms,CLA and peak to valley). Alumina abrasive grains (Al2O3) are used with average sizes (80, 40, 20, 7 μm) respectively. After 2 min lapping for each fraction of grains the following RMS are obtained 1.39, 0.57, 0.51, 0.33 μm. The corresponding peak to valley are respectively 7.5, 3.66, 2.88, 2.10 μm. The grains wear was characterized by the grains edges wear (roundness) and by their fractures. An optical microscope (CMM Scope Check) and a SEM are used for their observation. The alumina grains size distribution was also studied using a laser diffraction particle size analyzer (Shimadzu Sald-2001). 相似文献
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在仿形原理的基础上,提出了一种异型玻璃外廓尺寸的检测方法,通过旋转运动与直线运动结合,将传感器采集信息进行数据处理和坐标变换后,获得待测异型玻璃外廓的尺寸,为外廓磨边加工的进行提供精确的运动轨迹.在此研究基础上,采用基于PC开放式数控方式,实现对异型玻璃外廓检测和磨边加工运动控制,并结合实际应用,从硬件设计、软件设计两个方面介绍了基于翠欧开放式运动控制器的异型玻璃外廓检测及磨边加工系统,最后进行了试验验证. 相似文献
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《Computer Integrated Manufacturing Systems》1993,6(3):195-203
This paper introduces a methodology and a set of tools that allow a manufacturing engineer to integrate programable work cells such as flexible machining cells (FMCs) and flexible assembly cells (FACs), linked by an automated transport system, into an FMS that can be reprogrammed easily for the inclusion of additional products, thus making small- and medium-size production runs economical. The proposed method is based on the multiactivity paradigm that separates activity executions from their coordination by viewing systems as a set of assignable executors controlled by a coordinator. In this view, an FMS has at least three layers: a top layer in which the work cells are considered as assignable resources that can be programmed to execute the activities required to produce a given product; a middle layer in which the elements of the work cells (robot arms, NC machines, vision systems, etc.) are the assignable resources that execute in the required order the various machining, assembly and/or transfer operations; and a bottom layer that controls directly the various actuators and sensors. Because of the wide variety of work cell elements, only the top two layers are considered here. At the top level a control computer is used to coordinate the activities of the work cells and the transport system, and at the middle level each work cell includes a coordinator that oversees the operation of its elements. This paper introduces the process activity language, PAL, a high level specification language that matches the multiactivity view and allows the specification of the production steps and the operation of the work cells in a highly structured way. A number of PAL-based tools that aid the manufacturing engineer, to check for specification errors, to configure the FMS to meet the various production constraints, and that simplify the design and programming of the coordinators, have been developed and are outlined here. 相似文献
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为了提高系统的信噪比,将系统滤波器引入过程控制系统,必定会产生某些不利因素,首先是系统模型阶次增高,其次是滤波器会产生相迟角。设计高阶且有滞后的控制系统是很困难的。一种可以方便地解决此类问题的方法是分离与协调方法,本文介绍其设计原理及仿真结果。 相似文献