梯形螺纹车削过程中的振动分析与应对措施

精度和表面质量决定了梯形螺纹的使用效率和寿命,分析梯形螺纹车削过程中的振动原因,并给出应对措施,以确保螺纹加工时的表面质量。     

数控二轴铣床加工曲轴连杆轴颈的方法

在曲轴加工中,由于加工连杆轴颈时,需要做主轴的偏心夹具,使连杆轴颈的轴线成为回转中心。而随着曲轴品种的增多和批量的下降,制造夹具越来越影响开发和生产产品的周期。为此,我公司自制数控二轴铣床,经输入特定程序,用三爪卡盘夹曲轴,以曲轴的主轴颈为回转中心完成了连杆轴颈的铣削。     

冲床脚踏操纵力大的原因分析与消除

冲床亦称曲柄压力机,使用中常会遇到这样的现象:操作者感到脚踏踏板时很吃力。究其原因,一般是装在曲轴左端的制动装置(见图)调整不当,即制动摩擦阻力矩达不到克服曲柄回转及滑块往复运动的惯性。由于惯性的作用,惯性力矩通过离合器外露部分加在挡块上的量增大,从而加大挡块和离合器外露部分表面间的摩擦力,导致操作时脚踏阻力增大。     

影响内燃机曲轴动平衡测试精度的关键因素

机车内燃机用曲轴动平衡试验中对平衡精度的影响因素和误差防治办法。如：标定位置及重量的选择、机架支撑系统刚度、万向轴自身动平衡和去重钻削深度对有效去重率的影响。绘制出经验图表,大幅度提高一次去重率,缩短检测时间。     

磨床砂轮的自动平衡方法及系统的实现

轴承沟道磨床砂轮的动平衡对保证零件加工精度至关重要，文中介绍了一种轴承沟道砂轮的自动平衡系统，及平衡系统实现的基本原理。     

关于RAMAZ5511烧瓦抱轴断裂现象的分析

卡玛斯自卸汽车是我单位公路施工的重要生产工具,在公路建设中起到了举足轻重的作用。经多年使用,机械各部已发生了不同程度的磨损。现就曲轴飞轮组出现的烧瓦抱轴断裂现象进行探讨,为尽可能分析其损坏原因,必须首先研究它在发动机工作中的作用及其受力情况。曲轴输出内燃机功率,并驱动内燃机自身的其它运动机构。要将连杆传来的力转复为扭矩,而把发动机的功率输出去。因而曲轴在工作中将受到不断变化的周期性燃气压力,往复运动部分的惯性力及回转运动的离心惯性力等,曲轴在以上力和力矩的作用下,而产生的循环交复应力,易引起疲劳损坏、曲轴受到燃气压力和往复、旋转运动质量惯性力及其力矩的作用。这些周期性变化的载荷,在曲轴各部分产生变曲、扭转、剪切、拉压等复杂交变应力,同时也造成曲     

WD型仪器在动平衡机改造中的应用

动平衡是高速旋转件在加工、装配和维修中必须进行的工序。平衡精度对产品的质量和使用寿命影响很大。平衡精度e就是转子的剩余不平衡量(gmm/kg),也就是转子的不平衡偏心距(μm)。因此,当转子以角速度ω旋转时就有不平衡振动速度eω(mm/s)。国际标准ISO1940划分的平衡精度等级就是按不平衡振动速度的上限值确定的。自0.16mm/s起,按2.5倍逐级递增进行划分。例如G0.4、G1、     

曲轴车工加工方法的发展方向

曲轴车工加工方法在现今车削加工中的应用最为广泛,相关工作单位适时对其进行深度研究探索,革新优化其各项操作技艺,不仅有利于提高实际工作质量和效率,也能最大限度地展现曲轴车工加工方法的应用优势。这是引导曲轴车工加工方法朝着高效有序方向进步发展的重要推动力,对工作人员提高自身工作质量具有一定的参考价值。     

曲轴磨床卡盘的改进

上海机床厂和我厂生产的曲轴磨床,结构简单、性能可靠,但其卡盘存在下述缺点:1.三爪卡盘装夹工件不方便,装夹时间长,不适应大批量生产.2.利用丝杆调定曲轴半径,丝杆有间隙,易造成半径误差.3.卡盘结构刚性差,加工零件精度较差.为此,我们为大批量生产曲轴的厂家设计了一种可调式连杆轴颈磨削装夹装置,经过两年多的使用,效果良好,加工效率提高近一倍,大大提高了加工精度.     

破碎机铜锥套的车削加工工艺

在普通的CW61100车床上,采用托架偏移的操作方法,用卡盘夹住辅助夹具、用滚动托架支撑铜锥套,通过刀具参数和加工顺序的合理选择,使加工过程中产生的振动和转动扭矩在辅助夹具中得到消除,顺利完成铜锥套的车削加工。     

Ambidextrous balance and channel innovation ability in Chinese business circles: The mediating effect of knowledge inertia and guanxi inertia

Drawing on organizational learning theory and literature on guanxi, this study examines how and why ambidextrous learning balance influences firm innovation capability in Chinese business circles. We propose a U-shaped relation between ambidextrous learning balance and firm innovation capability which is mediated by guanxi inertia and knowledge inertia in different ways. Specifically, ambidextrous learning balance has an inverted U-shaped impact on guanxi inertia and further influences firm innovation capability. Whereas, ambidextrous learning balance has a linear positive influence on innovation capability through a decreased level of knowledge inertia. Based on survey data collected from, The results obtained from a sample of 197 Chinese channel enterprises using SEMs analysis provide strong support for our hypotheses. In addition, the findings based on firms with unbalanced ambidextrous learning indicate that as opposed to exploratory learning, higher level of exploitative learning leads to an increase in guanxi inertia and a decrease in knowledge inertia. These conclusions reveal how ambidextrous learning balance influence innovation capability for a firm with inherent learning preference which is not discussed by the extant research. At the same time, this study fills the gap of ambidextrous learning balance by considering the influence of culture. Our work also informs foreign practitioners of the optimal ways of learning for innovation in China.     

数控机床交流伺服装置

交流伺服装置是数控机床的执行环节,其性能在很大程度上影响机床进给系统的品质。本文介绍一种新的脉宽调制及自动调节的方法即把正弦波信号转换成脉冲宽度变化的调制波去驱动交流伺服电机,利用闭环系统自动调节输出交流伺服电机的电压,稳定转速,提高机床的加工精度。     

Let chaos reign,then rein in chaos—repeatedly: managing strategic dynamics for corporate longevity

Combining longitudinal field research and executive experience, we propose that corporate longevity depends on matching cycles of autonomous and induced strategy processes to different forms of strategic dynamics, and that the role of alert strategic leadership is to appropriately balance the induced and autonomous processes throughout these cycles. We also propose that such strategic leadership is the means through which leadership style exerts its influence on corporate longevity. Our findings can be related to organizational research on structural inertia, learning and adaptation, as well as to formal theories of complex adaptive systems. They also contribute to resolving the seeming contradiction between a study of corporations that attributes exceptional long‐term success to leadership style, and the more common proposition that strategy is the determinant of long‐term performance. Copyright © 2007 John Wiley & Sons, Ltd.     

加工中心的工艺特点及合理使用

根据加工中心使工件在机床上一次安装后由数控程序实现多种工序高度集中加工的工艺特点,提出了合理使用加工中心的9条建议,并对加工中心使用中遇到的热变形、残余应力对零件精度的影响以及切屑处理的困难提出了解决办法。     

Relationship between innovativeness,quality, growth,profitability, and market value

The purpose of this study is to examine the relationship between innovativeness, quality, growth, profitability, and market value at the firm level. Building on concepts from a resource‐based view of a firm and organizational learning, innovation and quality literature, we propose the innovativeness–quality–performance model, which describes how a firm's capability to balance innovativeness with quality drives growth and profitability, and in turn drives superior market value. Results of structural equation models indicate that (1) innovativeness mediates the relationship between quality and growth, (2) quality mediates the relationship between innovativeness and profitability, (3) both innovativeness and quality have mediation effects on market value, and (4) both growth and profitability have mediation effects on market value. Implications for theories and practices are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Mental representation and the discovery of new strategies

Research summary : Managers' mental representations affect the perceived payoffs and alternatives that managers consider. Thus, mental representations affect how managers search for profitable strategies as well as the quality of strategies they discover. To study how mental representation and search interact, we formally model the dual search over possible representations and over policy choices of a strategy “landscape.” We analyze when it is preferable to emphasize searching for the best policies rather than the best mental representation, and vice versa. We show that, in the long run, a balance between the two search modes not only results in better expected performance, but also reduces the variation in performance. Additionally, the article describes conditions under which increased accuracy of mental representations can actually worsen firm performance. Managerial summary : Managers' mental representations affect the perceived payoffs and alternatives that managers consider. Thus, mental representations affect the quality of strategies managers can discover. We analyze a computer simulation of how managers use mental representations to search for strategies. This sheds light on how managers should deal with the trade‐off between searching for policies and searching for representations; that is, whether managers should think creatively about how to represent a strategy problem or whether they should just stick to the current problem understanding, and try to find ways to improve performance as suggested by the current representation. We provide insight regarding the balance between the two search modes and describe conditions under which increasingly accurate mental representations can worsen firm performance. Copyright © 2015 John Wiley & Sons, Ltd.     

提高多参数组合仪测井质量的技术方法

针对油田动态监测测井中较为常用的多参数组合测井仪器，从传输方式以及测量精度上进行了定性的分析研究。提出了提高测井质量的技术方法，总结了实践经验，对于提高动态监测质量是行之有效的。同时还阐述了仪器发展的技术途径和方向。     

PCA在大型工程目标集成化动态分析上的应用

质量、费用及工期是大型工程项目管理的三大控制对象,通过建立大型工程项目质量、费用和工期的指标体系,利用多元统计分析中的PCA,将影响大型工程项目质量、费用和工期目标的17个因素进行降维处理,得到6个主成分,计算并比较6个主成分特征向量绝对值的大小进行重新归类,对比归类后的6个主成分得分排名和综合评价得分排名,进行大型工程目标集成化动态分析。最终案例分析的结果表明,结论符合实际大型工程项目管理的可能情况。     

Uncertainty and inertia

The challenge, and justification, of long-term telecommunications planning lies in an acute conflict between uncertainty and inertia. A national telecommunications system faces great economic, social, and political uncertainties, yet it does so handicapped by a degree of inertia which precludes rapid changes of direction. Assessing first the sources of uncertainty and inertia, the author goes on to examine ways in which the two can be reduced or reconciled.     

钻完井区域化管理模式在渤海油田的实践与应用

分析了渤海辽东湾区域钻完井作业存在物料供给距离远、补给周期长,现场物料消耗大、需求紧张,船舶与物料费用高等问题。通过设置区域总监积极参与船舶、物料动态管理,优化船舶安排、重点租赁工具跟踪、作业点区域化管理,提高了船舶使用效率,满足了现场需要,达到了供需平衡,节省了运输成本。