虚拟装配中装配公差的检验分析

Study of checking analysis on assembly tolerance in virtual assembling

装配性能分析的主要内容之一是装配公差的分析。阐述了虚拟装配系统中公差并行设计的过程,建立了零件尺寸公差与装配体配合公差的模型,利用约束关系图表达了零件尺寸信息与装配体配合关系信息,利用尺寸公差模型与约束关系图通过有关算法生成装配尺寸链。介绍了公差分析的两种方法,并以孔轴的径向配合为例,利用极值法进行装配公差检验,针对检验时出现的各种不合理结果进行了详细分析,并提出了设计公差相应的修改意见。

One of the main contents of analysis on assembly property is the analysis of assembling tolerance. The process of tolerance concurrent design in the system of virtual assembly has been expounded. The models for dimension tolerance of component parts and fitting tolerance of assembling body were established. The dimension information of parts and fitting relation information of assembling body were expressed by means of utilizing the constraint relation graph; and using model of dimension tolerance and constraint relation graph and through corresponding algorithm to generate the dimension chain of assembly. Two methods of tolerance analysis have been introduced, and taking the radial fitting of hole and shaft as an example to carrying out checking on assembly tolerance by extreme value method. Aimed at various kinds of unreasonable resuits appeared at the time of checking to conduct analysis in detail and the revision suggestions corresponding to the designed tolerance were put forward.