压铸机合型力检测

压铸机合型力是一项重要的压铸工艺参数。针对不同吨位压铸机合型力检测的特殊要求,研制了位移式和应变式传感器,介绍了它们的工作原理及其特点。应用结果表明,它们可以满足在线检测合型力的要求。     

直流电阻箱检定装置测量不确定度的评定

重点论述了直流电阻箱检定装置的不确定度来源，并对此检定装置的不确定度进行了分析与计算。     

钢板断后伸长率测量不确定度的评定

为评定钢板断后伸长率的测量不确定度,以轧制厚度为18mm的Q235B板材矩形带头短比例试样为 例,建立了不确定度计算的数学模型,确定了影响试验结果的各项因素:如断后标距Lu、原始标距L0,计算出了各因素的标准不确定度,得出结果的扩展不确定度,并给出最终测量结果的表达式:断后伸长率的最终测量结果为 (28±3)%。     

检测实验室的测量不确定度评定

随着入世,中国的国家实验室认可工作已广泛开展,测量不确定度的评定是认可实验室的一项重要工作。检测实验室的测量不确定度评定会常常遇到问题,笔者就检测实验室内开展不确定度评定工作简谈自己的见解。     

力学测试中的不确定度评定

简要介绍了测量不确定度的基本概念,同时对力学测试中测量不确定度的评定过程和基本方法进行了论述。评定了力学测试中钢材拉伸试验的相对不确定度,验证了实验室日常检测结果的可靠程度。     

金属夏比冲击试验测量结果不确定度评定

以测量标准试样冲击值水平28．6J、81．9J、127．1J和224．5J为例,根据JJF1059-1999测量不确定度评定与表示和CSM01 01 02 01-2006推荐技术和方法,对测量过程中的不确定度来源进行了分析,采用A类、B类的评定方法对各种因素引起的不确定度分量、合成不确定度、扩展不确定度进行了评定,并给出了评定结果。     

力学测试不确定度的评定

讨论了测量不确定度的来源和力学测试中测量不确定度的影响因素，介绍了一些力学测试测量不确定度评定的实例。     

金属材料布氏硬度测量结果不确定度的评定

笔者对金属材料布氏硬度试验中的测量不确定度来源进行了分析，而且借助于KB3000BVRZ全自动硬度试验机对布氏硬度测量结果的不确定度进行了详细的评定，最终给出了扩展不确定度。     

玻璃液体温度计示值修正值测量结果不确定度的评定

结合实际检测工作，根据JJG 1059—1999《测量不确定度评定与表示》计量技术规范的要求，对工作用玻璃液体温度计示值修正值测量结果进行了不确定度分析与计算。其结果对工作用玻璃液体温度计的检定与校准工作具有一定的参考价值。     

布氏硬度试验中测量不确定度的评定

介绍了测量硬度不确定度的原理，并以金属材料布氏硬度试验结果的不确定度的评定作为不确定度在理化检验中应用的一个实例。     

Die closing force in low pressure tube hydroforming

Recently, low pressure tube hydroforming has emerged as a technology to reduce the weight of automotive body structures by allowing the implementation of advanced high strength steels and minimizing the number of process steps. In this study, a simplified analytical model based on a rigid, perfectly plastic material model was developed to determine the die closing force needed to form a simple geometry using the low pressure hydroforming process. The analytical solution developed was compared with experimental and numerical results; this demonstrated a reasonable accuracy of the model which will assist in the understanding of the basic principles governing the low pressure hydroforming process.     

Evaluation of cutting force uncertainty components in turning

A procedure is proposed for the evaluation of those uncertainty components of a single cutting force measurement in turning that are related to the contributions of the dynamometer calibration and the cutting process itself. Based on an empirical model including errors from both sources, the uncertainty for a single measurement of cutting force is presented, and expressions for the expected uncertainty vs. cutting parameters are proposed. This approach gives the possibility of evaluating cutting force uncertainty components in turning, for a defined range of cutting parameters, based on few experiments.     

实验室检测评定方法的测量不确定度

检测评定方法是实验室中最为常用的基础试验手段,其评价判定结果的准确性对研究材料特性及评价制品的合格与否都有直接参考价值。使用名义等级(nominal level)、次序等级(ordinal level)、度量等级(metric level)这3种不同评价等级方式,再通过对物理检测、化学检测、无损检测(NDE) 3种试验过程不确定度的分析和评价,最终获得了不同检测评价方法所合成不确定度评定的不同结果。测量结果的准确性往往会对企业的经济利益造成直接影响,甚至会影响到员工人身安全和健康,因此,该研究对国内外实验室检测评价方法的不确定度评定有着很重要的意义。     

浮动凹模闭塞挤压力的计算方法研究

以冷挤压十字轴为例,通过合理的锻件分割办法,以锻件的1/4为研究对象,把浮动凹模闭塞挤压的总压力看作单个小轴近似的正挤压力、坯料与凹模侧壁的摩擦力以及浮动凹模的合模力三者之和,由此提出了一种闭塞径向挤压力的计算方法。将此计算结果与Deform-3D数值模拟结果对比后,又分别以三叉轴与两叉轴的几种锻件为例对该计算方法进行验证,证明了该计算方法的科学性。并在上述验证比对的基础上对该计算方法提出了一定的修正办法,进一步减小了误差。     

Modular system to measure and control the force distribution in deep drawing processes to ensure part quality and process reliability

Force distribution is one of the most important variables in deep drawing. Together with the tribological conditions, it determines the quality of the formed component. This paper presents a novel mechatronic system for measuring and controlling the normal force distribution in deep drawing. The concept is based on an arrangement of a force measuring platform between the upper die and the press ram. Furthermore, its modular design with multiple sensors allows it to be applied to any tool shape. Using the location of the resulting total force enables novel approaches in the process evaluation. Experimental investigations with the measuring system in a controlled process show the potential of new methods to increase process reliability.     

汽车消声器纵缝咬边机芯模胀合技术

介绍了汽车消声器纵缝咬边胀合技术及其咬边芯模机构的设计计算。     

An analytical assessment of measurement uncertainty in precision inspection and machine calibration

Dimensional inspection is commonly used to scrutinize the quality of manufactured products against the established standards and specifications. Meanwhile, dimensional measurement of an artifact is also commonly used as one of the methods for machine-performance calibration. However, the quality and reliability of many inspection and measurement processes are often contaminated by various uncertainties. Two prominent sources for measurement uncertainties are: (a) the imperfection of a measuring device, and (b) the dimensional deviation and geometric characteristics of a measured feature. Usually, the effects of both types of uncertainty are compounded by one another. To ensure the quality and reliability of any inspection process, measurement uncertainty needs to be addressed for all data acquisition activities. A method is also needed to identify and decouple the effect of compounded uncertainties. If this can be done, then the data collected can be properly adjusted and a more meaningful analysis result can be drawn. In this paper, the issues of uncertainty identification for machine calibration and dimension measurement using artifacts with various geometric features are discussed. Analytical models are derived first to identify and then decouple the compounded effect of both types of uncertainties. Finally, case studies are used to illustrate the procedures for both identifying and decoupling the compounded effect of the measurement uncertainties.     

板料折弯机自由折弯时折弯力计算

目前,常用的折弯力计算公式都是从国外样本中移植过来的,对于其来历和适用范围尚无资料说明.本文系统论述了折弯力计算公式的推导过程以及必须满足的参数条件.为了扩大适用范围,介绍了一种计算折弯力的新方法.     

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介绍了一种全新设计的材料扭转试验机,主要采用了液压回转式夹具装夹试样,通过伺服电机—滚珠丝杆—传感器方式对长线材试样施加恒定的拉紧力,以及伺服电机—减速机构驱控夹头双向旋转,可针对Ф7 mm~Ф14 mm、2 000 MPa级长线材试样开展各类扭转以及低成本的慢速拉扭复合疲劳试验。基于对试样扭矩变化的实时跟踪,可实现0.000 5~30 r/min的变速扭转以及在扭矩陡降(即最大扭转塑性)瞬时临界采样,供后续试样内部组织与外表面形貌评价分析。     

复杂不确定性过程中基于智能的多模态控制策略

数学模型难以描述复杂不确定性的过程.为了避免复杂不确定性过程控制中用数学范式建模与控制的困境,探索了一种基于无模型的智能控制策略.基于分解协调原理,对过程控制的难点进行了剖析,总结了底层复杂不确定性过程的控制论特征,研究了面向独立子过程的无模型多模态智能控制策略,并构造了一种多模态控制算法.实验仿真的响应曲线表明:基于仿人智能控制的多模态控制策略能获得预期的良好控制品质.研究结果表明:提出的多模态控制策略是合理可行的.