修配法在调整数控车床前后顶尖不等高度中的应用

讨论了数控车床前、后顶尖中心轴线产生不等高度的原因,提出采用修配法解装配尺寸链,通过调整尺寸链中的修配环来保证装配需要的精度。通过对修配法求解装配尺寸链在调整数控车床前后顶尖的模型分析、编程和事例验证显示,以及修配法解装配尺寸链适合调整机床前后顶尖不等高度的计算,并将计算程序化,提高了数控机床的装配或维修效率。     

注射成型零件尺寸链的分析与计算

根据尺寸链原理，对在不同成型零件装配过程中，由不同工作尺寸组合和累积形成的工作尺寸的计算，进行分析探讨，提出了采用修配法来保证此类工作尺寸精度要求的判断标准及如何确定其合理的修配补偿量     

尺寸类型及其对封闭环的影响分析

本文详细分析了修配环尺寸两种类型包容尺寸和被包容尺寸，以及它们在装配尺寸链中作为增环和减环对封闭环大小的不同影响情况，因此，有助于加深理解用修配法角装配尺寸链的基本概念。     

用修配法装配时尺寸链的计算

用修配法装置可获得较高的装配精度，修配环修配量的确定是该装置配法的主要问题，本文仅对此进行阐述。     

挤压筒装配的研究

挤压筒的内衬与外套装配过盈量决定着热装应力，即决定着挤压筒内衬的工作寿命，通过理论计算，得出装配合理的过盈量，并根据蠕变结果增加补偿量，不但使内衬应力分布均匀，也可对外套实行补偿修配，提高了挤压筒外套的利用率和可靠性。     

八一钢厂1420轧机修配工艺技术开发

本文主要阐述了轧机中的关键件油膜轴承部分以及相关件的修配工艺方案，为二手轧机生产线的修配提供一些切实可行的加工方法。     

压力机连杆表淬圆弧面加工新工艺与拓展应用

压力机连杆小端圆表淬弧面加工的传统工艺为数控精铣后表淬,最后钳抛配研。该工艺对机床加工精度要求极高,但因连杆小端圆弧面表淬后硬度高常规无法加工,淬火面容易产生形变,后期通过钳修配研工作量巨大且效果不佳,满足不了设计和装配要求。新工艺通过改进加工工艺方案,半精铣表淬后,设计专用磨削刀具,采用数控磨削,极大提高了小端圆弧面的加工质量和装配精度,显著降低了生产成本,收到了良好的效果。     

压铸模数字设计中的虚拟装配策略研究

虚拟装配是实际装配过程在计算机上的实现。通过实例探讨了虚拟装配方案规划问题，介绍了一种基于子装配的装配结构模块化虚拟装配策略，并运用这一策略对阀盖压铸模进行了虚拟装配；改进了现有虚拟装配方式，提出了同步虚拟装配策略并给出了实现方法。作为数字设计的组成部分，同步虚拟装配简化了虚拟装配的工作过程，为面向装配的数字设计提供了手段，对于分析、评价和完善设计对象，确保实际制造一次成功有重要意义。     

修配环尺寸的简明看图解法

本文提出了修配环尺寸的看图解法，该方法很容易得到计算公式，直观，简明。     

基于数字孪生的装配过程质量控制方法

针对飞机机翼装配过程中装配累计误差大,返修率高等问题,对数字孪生技术在装配过程中的应用进行了研究。提出基于数字孪生的装配过程质量控制方法,通过构建数字孪生车间并使用各种数字化装配和检测设备对装配数据进行实时采集和分析,在研究和分析历史装配质量数据的基础上,通过Copula理论构建质量控制点之间的相关性模型,再借助装配质量熵和互信息理论构建产品装配稳定性测度模型,对装配质量控制点控制阈进行优化,预测并给出下一步的最优化装配方案,将最佳装配方案传送到物理车间进行实际装配。最后,在某车间以某型号机翼翼盒装配为例,对原型系统进行了应用验证,证实了整套方法的可行性。     

基于小位移旋量公差建模和蒙特卡洛模拟的装配体公差优化设计方法北大核心

提出一种基于小位移旋量(SDT)公差建模和蒙特卡洛模拟的装配体公差优化设计方法,通过分析装配精度链、装配结合面和结合面公差3个对装配精度具有重要影响的核心要素之间的关系,利用SDT理论和蒙特卡洛模拟法建立公差模型,再利用齐次变换理论建立结合面误差模型和装配精度模型,进而推导出装配体装配精度与结合面公差相关的映射模型;结合公差制造成本、装配精度可靠度原则,建立装配体装配精度的公差优化模型,并以顶尖装配体为例完成公差优化分析。研究发现:在满足装配精度可靠度的前提下,可使顶尖装配体加工成本降低9.02%,而装配精度可靠度提高至97.81%,验证了所提方法的有效性。     

零件装配中动态尺寸链的研究

文章提出了零件装配中的动态尺寸链概念，阐述了研究动态尺寸链的必要性以及静、动态尺寸链的计算方法，举例阐述了一种按动态尺寸链的方法来计算保证装配精度的应用。由此可见动态尺寸链的研究是今后的零件制造和装配中一个重要的研究内容。     

Study of an assembly tolerance allocation model based on Monte Carlo simulation

The traditional design methods of assembly tolerance allocation are usually based on engineers' experience, or the worst on worst tolerance analysis (WOW) method, or the root sum square tolerance analysis (RSS) method. However, the above-mentioned methods, whilst used frequently in the analysis of a single-dimensional chain, are not suitable for the analysis of geometrical tolerance and multi-dimensional chains. Also, the relationship between tolerance and manufacturing cost is not considered and a suitable tolerance allocation based on minimum manufacturing cost can not be obtained. Some research works have applied linear or non-linear programming methods to optimize the tolerance allocation of each part in an assembly. However, the convergence of the solution is not ensured. The purpose of this study is to provide an integrated approach, including tolerance design, manufacturing cost analysis and multiple chains consideration, using the Monte Carlo method to optimize the tolerance allocation with minimum cost. The Monte Carlo method, a statistical simulation method, was used to simulate the dimension variance of each part and each dimensional chain. The contribution percentage of each part on each dimensional chain was calculated. Tolerance cost was chosen as an object function and the tolerance allocation model as a constraint condition, the optimum tolerances of each part being obtained by the iteration method. Results of computer simulation for several examples were compared with published data for demonstrating the feasibility of the proposed method. It can be concluded that the tolerance-allocation model combined with a tolerance-cost relationship can provide a very practical and useful approach for design engineers.     

基于3 DOF并联机器人的误差分析

目前使用比较广泛的公差分析方法是通过装配尺寸链得到公差设计函数,但该方法不能有效适用于结构复杂且精度要求极高的机器人制造业。基于仅考虑主动关节误差的情况下,通过误差数学模型的建立,对定向误差以及位置误差进行分析,进而得到三自由度并联机器人的结构的详细分析结果,并提供了基于数值分析方法在给定标称配置下计算机器人定向误差和位置误差的有效方法。     

一种以流动单元体为载体的精密传感器自动

精密传感器自动化装配线的设计采用以流动单元体为载体，转动链条推动单元体运行，并且在装配线站点处设置流动单元体气动阀自动供气接口，用于单元体接气推动治具动作，从而实现对精密细小零件的快速精密定位和装配。利用西门子S7 300PLC的PROFIBUS网络通信模式，设置装配工位、检测工位，实现整个装配过程的自动控制和检测。     

Product variety and manufacturing complexity in assembly systems and supply chains

Mixed-model assembly systems and modular supply chains are enablers to high product variety. However, as variety gets very high, the assembly and supply processes can become very complex. In assembly systems, the complexity may cause human errors and in turn impacts system performance. The complexity also impacts supply chain configuration and inventory control policy. This paper proposes a unified measure and models of complexity to assist in designing systems with robust performances. Complexity is defined as an entropy function of product variety and models are developed to describe the complexity propagation in multi-stage assembly systems and multi-echelon supply chains. Applications of the models are presented for complexity mitigation.     

基于轴系尺寸链设置缺陷导致机械系统失效后的改进分析

机械系统中支承结构设计以及轴系尺寸链设置将直接影响其运转安全性和可靠性。本研究分析了油雾分离器结构原理和工况条件,明确了两端固定支承的机械系统在运转过程中,其一端轴承外圈端面与壳体孔应保留适当间隙,以适应轴的热伸长。就外场发生的失效开展分析和定位,从失效件外观形貌和理化检测结果确认,轴承在过大轴向附加载荷作用下产生爬坡,进而导致轴承短期内产生高温失效。为验证失效轴承附加轴向载荷是否与轴系尺寸链设置直接相关,开展装配尺寸链核算,确认失效轴承外圈端面与壳体孔之间存在极大的干涉风险,失效与轴系尺寸链设置不合理有关。针对失效定位提出装配前选配零件、调整零件公差等改进措施,同时建议对该间隙进行检测。     

螺母拧紧机实时检测系统设计

通过对汽车分动器主动齿轮总成的力封闭性、分流性和尺寸链封闭性分析和研究，得出了调整垫片的厚度对主动齿轮总成性能影响的实质。此实时检测系统是在原有的螺母拧紧机系统基础上设计、开发出来的，可以在拧紧过程中实时显示主轴拧紧力矩和主动齿轮总成的轴承预紧造成的轴承座阻力矩。根据这两个扭矩值，可以判定调整垫片的选垫厚度是否合适。     

A computer aided chaining approach for predicting the shape accuracy in manufacture of automotive structures

The increasing competition and the urge to reduce costs and shorten product-life-cycles in the automotive industries imply the application of virtual manufacturing mock-ups. Computer aided engineering methods including simulations of the structural behavior during manufacturing and assembly contribute to eliminate trial-and-error along the production chains of vehicle structures. Such digital mock-ups also provide an input for additional tolerance analyses and allow the identification of the pending quality of structure components in advance. In this way large numbers of experiments and adjustments on the existent production lines can be avoided. In this paper an approach is introduced, which allows the replication of the physical effects along manufacturing chains based on thermo-mechanical models. The rendered results after considering successive operational steps provide the basis for initial estimations regarding the shape accuracy of structure assemblies. For a specific example of the automotive body-in-white a first run of a manufacturing process chain is investigated in order to predict the shape quality of a probable production cycle by applying a tolerance chain analysis. The results enable the scrap identification due to non-satisfied quality of assemblies. Finally, based on the achieved results a re-engineering of the manufacturing chain is suggested in order to fulfill quality requirements.