分组装配中零件尺寸及偏差的计算

本文对分组装配中零件尺寸及偏差的确定进行了研究，提出了分组装配中零件分组尺寸及偏差确定的新方法-尺寸链计算法，给出了确定各组基本尺寸及偏差的计算公式，为正确确定分组装配各工艺尺寸提供了理论依据。     

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     

塑料模成型零件工作尺寸的计算

成型零件的工作尺寸可分为独立工作尺寸和关联工作尺寸，而目前尚无关联工作尺寸的计算方法。采用尺寸链的计算方法阐述了型芯，凹模的径向尺寸，型芯高度，凹模深度尺寸作为独立工作尺寸，特别是作为关联工作尺寸时的计算方法，并分析了影响塑件壁厚尺寸精度的因素。     

计算机辅助二维装配尺寸链分析计算关键技术研究

针对复杂二维装配尺寸链分析计算中的主要问题进行了讨论，对计算过程中的几项关键技术进行了深入的研究，并开发出计算机辅助二维装配尺寸链计算软件。     

谈谈零件工艺尺寸链计算中尺寸换算问题

谈谈零件工艺尺寸链计算中尺寸换算问题安徽农业大学方筱萍在零件工艺尺寸链中最常碰到的反计算问题就是尺寸换算──这是已知尺寸链封闭环尺寸公差。求某一组成环尺寸公差的反计算问题。在零件机械加工过程中，经常出现基准不重合的情况。如为了便于加工或测量，会出现原...     

工艺尺寸链的图解方法

工艺尺寸链的图解方法安徽农业大学工艺教研室方筱萍主题词：尺寸链，图解法，加工余量在编制工艺文件时，为了拟订合理的加工余量、工艺尺寸及公差，保证零件加工的尺寸精度，需要进行尺寸链计算；而在校阅工艺文件时，验算尺寸链计算的正确与否，也是一项必须进行的重要...     

微分和概率理论在模具尺寸链计算中的应用分析

根据模具零件尺寸链的解算目标要求和其数学特征,分析了3种尺寸链计算方法的特点以及具体适用的场合,对保证模具零件的尺寸精度和降低制造成本有参考价值。     

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。     

装配图参数化在模具设计中的应用

针对模具装配图设计，在零件图参数化的基础上，通过装配建模记录零件之间的装配关系，从而在装配模型实例化时自动产生相应零件图的变换矩阵；通过对装配尺寸、零件配合尺寸、零件尺寸及零件详细设计信息分级处理，来保证零件图和装配图的一致性以及在装配图设计的同时生成零件图。     

装配图参数化在模具设计中的应用

针对模具装配图设计，在零件图参数化的基础上，通过装配建模记录零件之间的装配关系，从而在装配模型实例化自动产生相应零件图的变换矩阵；通过对装配尺寸，零件配合尺寸，零件尺寸及零件详细设计信息分级处理来保证零件图和装配图的一致性以及在装配图设计的同时生成零件图。     

汽车包边质量前期控制方法

通过在前期设计阶段对包边总成问题进行研究,旨在预防及控制包边总成问题点,以提升汽车整车外观及尺寸精度,避免后续生产过程中包边零件产生质量问题,可为包边零件、包边模结构、工艺设计提供参考。     

基于Windows平台的焊接工装夹具三维参数化CAD

基于Ｗｉｎｄｏｗｓ平台,以ＡｕｔｏＣＡＤ ｆｏｒ Ｗｉｎｄｏｗｓ为支撑软件,利用其ＡＤＳ开发系统,针对焊接工装夹具的多样性,采用模块化、渐增式开发式和三维参数化设计以及面向对象程序设计方法,建立了焊接工装夹具ＣＡＤ（ＷＦＣＡＤ）系统。系统具备能完成从焊件原始信息处理到夹具的基本尺寸、结构尺寸的设计与计算、三维模型图生成和三维动态结构模拟以及由三维模型图生成装配图和零件图的功能。ＷＦＣＡＤ系统具有扩充性好和开放性的特点,并采用标准的Ｗｉｎｄｏｗｓ人机对话界面,直观,简洁。     

柔性制造系统中组合夹具的设计研究

文章对组合夹具在柔性制造系统中的应用现状做了简要介绍,重点讨论应用三维实体造型软件Pro/ E进行计算机辅助组合夹具设计过程,包括建库、创建工件模型、装配、装配体分析以及相关信息的处理等步骤的阐述.以此来说明计算机辅助夹具设计的研究应用将促进制造业柔性化发展.     

支持数字化装配系统的数据库技术

通过对数字化装配系统数据存取的需求分析,在SQL Server平台下,建立了装配模型库、装配过程库、装配知识库和装配环境库。提出了产品装配模型的三部分信息的存储方式,建立原始信息库、动态添加库、动态记录库分别存储相应的零部件自身属性信息,提出了以配合零件对为基本存储单元的动态记录库记录零件间的配合特征信息。它们有效地支持了数字化装配系统的各功能模块。     

Integration of mechanical testing with automated parts handling in a production environment

With the emphasis on zero defects, 100% inspection is becoming a norm in manufacturing industry. In addition to dimensional and functional tests, particular mechanical tests are conducted by applying a load-deformation cycle on a component/assembly. Traditional off-line techniques, using Instron-like test machines, are not suitable for 100% inspection. Automated parts handling, using devices such as robots, is being used increasingly in production lines. The present paper examines the possibility of conducting mechanical tests with industrial robots, used for parts handling. These proposals are based on the authors' research in the area of fabric testing using robotics. This paper extends these into the wider arena of parts handling.     

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UG的RV减速器虚拟样机设计与运动仿真分析

以某型号RV减速器为研究对象,根据其传动原理,利用UG参数化建模技术,建立RV减速器各零部件模型,根据RV减速器结构特点以及零部件装配关系,进行虚拟装配和干涉检测。详细介绍了运动仿真过程中连杆定义、运动副设置,以及驱动施加载荷的方法步骤,得到中心轮、行星轮、外壳、摆线轮的加速度图像。结果表明：减速器在很小的范围内周期性振动,结构紧凑,运行平稳,能量损失小。为后续减速器的启动特性分析、噪声振动分析、故障诊断等的深入研究打下基础。     

A parametric study of joint performance in sheet metal assembly

In sheet metal assembly, joints are designed to facilitate welding the parts and to form various shapes and dimensions of sheet metal products. The most commonly used joints are lap joints, butt joints and butt-lap joints. Different joint configurations have different performance characteristics. One of the performance criteria is the level of dimensional variation in the assembly. This paper presents a parametric study of the dimensional variation characteristics of the three basic joints. An offset finite-element-model-based variation simulation methodology is used in the parametric study in order to take into consideration possible part deformation. This parametric study helps determine the circumstances under which part variation or tooling variation will contribute more variation to assembly variation. These results provide improved understanding of sheet metal assembly processes and provide data for robust product/process design.     

面向产品的CAPP装配工艺决策

在CAPP中,面向产品装配设计过程,主要问题是如何建立产品与各个零部件之间的装配关系,如何创建装配空间。针对配电设备,论文对配电产品装配信息描述及产品装配过程进行研究,分析了CAPP中产品装配决策过程,并给出实例。     

Quality-driven Sequence Planning and Line Configuration Selection for Compliant Structure Assemblies

Assembly sequence planning is an integral part of a new product and process development. However, currently there are very few available approaches to evaluate the impact of assembly sequences on product quality. This paper develops a methodology for Quality-driven Sequence Planning (Q/SP) with consideration to product dimensional quality based on the following three steps: (1) Sequence generation for predetermined line configurations using /(-piece mixed-graph representation of assembly; (2) Dimensional quality model of variation propagation for assembly processes with compliant parts; and (3) Evaluation of sequences based on the multivariate process capability index. The methodology is illustrated using an industrial case study.